Shell-and-tube condenser capable of automatically removing liquid film

Abstract

The invention relates to the technical field of heat exchangers, and discloses a shell-and-tube condenser capable of automatically removing a liquid film, which comprises a shell, one end of the shell is provided with a cold water inlet, the other end of the shell is provided with a cold water outlet, the upper end of the shell is provided with an air inlet, and the lower end of the shell is connected with a liquid outlet pipe; a plurality of air uniformizing holes are formed in the air uniformizing cover, the air uniformizing cover divides an inner cavity of the shell into a first cavity body and a second cavity body, a second finned tube is arranged in the first cavity body, a first finned tube is arranged in the second cavity body, and liquid guide fins are arranged on the outer wall of the first finned tube. The finned tube I is arranged, and the liquid guide fins are additionally arranged on the finned tube I, so that the continuity of a liquid film is actively destroyed, the liquid film does not accumulate and grow outside the tube, but accumulates in the liquid guide fins to drop in a liquid drop form, and the problem of thermal resistance caused by liquid film coverage is effectively solved; and the heat transfer efficiency of the whole equipment is obviously improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat exchanger, in particular to a tube-shell condenser capable of automatically removing liquid film. BACKGROUND

[0002] The tube-shell condenser is widely used in chemical industry, refrigeration and other fields, and its heat transfer performance is directly related to the energy efficiency and economy of the whole system. In the gas-liquid condensation process, the gas phase working medium changes phase on the outer surface of the low-temperature tube wall to exchange heat. The existing tube-shell condenser has the following shortcomings: as the operation time of the condenser increases, the thickness of the continuous liquid film formed during the condensation of the gas phase working medium on the outer tube wall increases, and the covering effect caused by the liquid film significantly hinders the direct contact between the gas phase working medium and the cooling surface, resulting in a significant decrease in the heat transfer coefficient and restricting the heat transfer performance of the equipment. Experimental studies show that the liquid film thermal resistance accounts for 60%-80% of the total thermal resistance, which seriously restricts the heat transfer performance of the equipment. The exhaust gas of the compressor has a certain superheat degree, and the superheated working medium first cools to saturation in the condenser, and the heat transfer process does not change phase, so the heat transfer efficiency is low, resulting in an excessively large condenser cylinder. In the outlet area of the condenser, there is a lack of effective subcooling structure design, and the condensed liquid is difficult to further cool to below the saturation temperature, and the insufficient subcooling degree will cause the liquid to flash in the subsequent process, affecting the stability of the system and causing energy waste. SUMMARY

[0003] The present application provides a tube-shell condenser capable of automatically removing liquid film to solve the above technical problems.

[0004] The technical solution of the present application to solve the above technical problems is as follows: a tube-shell condenser capable of automatically removing liquid film, comprising a shell, one end of the shell is provided with a cold water inlet, the other end is provided with a cold water outlet, the upper end of the shell is provided with an air inlet, the lower end of the shell is connected with a liquid outlet pipe, the shell is provided with a gas equalizing cover, a finned tube one and a finned tube two, the gas equalizing cover is provided with a plurality of gas equalizing holes, the gas equalizing cover divides the inner cavity of the shell into a first cavity and a second cavity, the finned tube two is arranged in the first cavity, the finned tube one is arranged in the second cavity, and the outer wall of the finned tube one is provided with liquid guiding fins.

[0005] On the basis of the above technical solution, the present application can also be improved as follows: Preferably, the lower end of the shell is provided with a liquid storage bag, the shell is provided with a partition plate and an integrated subcooling unit, the partition plate is located at one end close to the cold water inlet, the partition plate cooperates with the inner wall of the shell to form a subcooling cavity, the integrated subcooling unit is located in the subcooling cavity, and the integrated subcooling unit is connected with the liquid storage bag.

[0006] Preferably, the equalizing cover is coaxially arranged with the shell, and two parallel equalizing plates are arranged at the upper end of the equalizing cover, and the height of the equalizing plates gradually decreases from the air inlet along the axial direction to both sides.

[0007] Preferably, the plurality of finned tubes are arranged in a square matrix in the second cavity.

[0008] Preferably, each of the finned tubes is provided with two liquid guide fins arranged at the separation area of the finned tube.

[0009] Preferably, the total height of the liquid guide fin in the radial direction is H, ; H is the total height of the liquid guide fin in the radial direction, m; is the wall thickness of the finned tube, m.

[0010] Preferably, the thickness of the liquid guide fin gradually decreases in the radial direction, and the thickness of the liquid guide fin is T, ; wherein T is the thickness of the liquid guide fin, m; and H is the total height of the liquid guide fin in the radial direction, m; is the wall thickness of the finned tube, m; and h is the height of the liquid guide fin at a certain radius in the radial direction, m.

[0011] Preferably, the finned tubes are arranged in a ring in the first cavity, and the distance between adjacent finned tubes is S, ; wherein: is the outer diameter of the shell, m; is the outer diameter of the equalizing cover, m; is the distance of the ring array, m; is the saturation temperature of the working medium, K; is the temperature of the working medium inlet, K.

[0012] Preferably, the inner diameter of the finned tube is , ; wherein: is the inner diameter of the finned tube, m; is the outer diameter of the shell, m; is the outer diameter of the equalizing cover, m; is the convective heat transfer coefficient inside the tube, W / m 2 ·K; is the convective heat transfer coefficient outside the tube, W / m 2 ·K.

[0013] Preferably, the integrated supercooling unit comprises two rows of tube bundles, the two rows of tube bundles extend along the radial direction of the shell, and the two rows of tube bundles are staggered.

[0014] The application has the advantages that: the application actively destroys the continuity of the liquid film by arranging the finned tube and adding the liquid guide fins on the finned tube, so that the liquid film does not accumulate and grow outside the tube, but accumulates in the liquid guide fins in the form of droplets, effectively solving the problem of heat resistance caused by liquid film covering, and the heat transfer efficiency of the overall equipment is significantly improved; the application realizes fine partitioning by arranging the gas equalizing cover, and realizes accurate management of each thermal process, so that the gas passes through different cavities to realize de-superheating, condensation and supercooling, so that the outlet liquid obtains sufficient supercooling degree; the application arranges the gas equalizing cover inside and optimizes the tube bundle arrangement to realize uniform distribution of the flow field, so that the gas phase working medium can be uniformly distributed around each finned tube after entering the condenser, avoiding the situation that the local concentration is too high or too low, thereby improving the overall heat transfer performance of the condenser, ensuring that the gas-liquid two-phase working medium fully contacts and efficiently exchanges heat in the condenser, and further improving the operation stability and economy of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 Structure diagram of the tube and shell condenser for automatically removing liquid film of the application; Figure 2 Cross-sectional view of the tube and shell condenser for automatically removing liquid film of the application; Figure 3 Cross-sectional view of the finned tube one of the application; Figure 4 Cross-sectional view of the finned tube two of the application; Figure 5 Front view of the integrated supercooling unit of the application; Figure 6 Side view of the integrated supercooling unit of the application; Figure 7 Schematic view of the gas equalizing cover of the application.

[0016] Fig. 1 is a cold water outlet; Fig. 2 is an air inlet; Fig. 3 is a gas equalizing cover; Fig. 31 is a gas equalizing plate; Fig. 4 is an integrated supercooling unit; Fig. 41 is a tube bundle; Fig. 5 is a cold water inlet; Fig. 6 is a liquid outlet pipe; Fig. 7 is a regulating valve; Fig. 8 is a liquid storage bag; Fig. 9 is a finned tube one; Fig. 91 is a liquid guide fin; Fig. 10 is a support; Fig. 11 is a partition plate; Fig. 12 is an upper liquid level meter port; Fig. 13 is a lower liquid level meter port; Fig. 14 is a shell; Fig. 15 is a finned tube two; Fig. 16 is a first cavity; Fig. 17 is a second cavity; Fig. 18 is a supercooling cavity; Fig. 19 is an impact area; Fig. 20 is a heat development area; and Fig. 21 is a separation area. DETAILED DESCRIPTION

[0017] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work should fall within the scope of protection of the present application.

[0018] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. The terms "vertical", "upper", "lower", "horizontal" and the like indicate the orientation or positional relationship shown in the drawings, and are only used for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0019] As shown in Figures 1 to 7 The present application discloses a kind of automatic removal liquid film shell and tube condenser, including shell 14, shell 14 is installed on support 10, one end of shell 14 is equipped with cold water inlet 5, the other end is equipped with cold water outlet 1, shell 14 is equipped with air inlet 2, the lower end of the shell 14 is connected with liquid outlet pipe 6, shell 14 is equipped with gas distribution cover 3, finned tube one 9 and finned tube two 15, gas distribution cover 3 is equipped with multiple gas distribution holes, gas distribution cover 3 separates the inner cavity of shell 14 into first cavity 16 and second cavity 17, wherein, first cavity 16 is formed between gas distribution cover 3 and the inner wall of shell 14, finned tube two 15 is arranged in first cavity 16, the inner side of gas distribution cover 3 is second cavity 17, and finned tube one 9 is arranged in second cavity 17, the outer wall of finned tube one 9 is equipped with liquid guide fin 91, liquid guide fin 91 extends along the axial direction of finned tube one 9, prevents liquid film thickness from increasing, and optimizes heat transfer.

[0020] Further, the lower end of shell 14 is installed with liquid storage bag 8, shell 14 is equipped with partition plate 11 and integrated supercooling unit 4, partition plate 11 is located at one end close to cold water inlet 5, partition plate 11 cooperates with the inner wall of shell 14 to form supercooling cavity 18, supercooling cavity 18 is located at one end close to cold water inlet 5, integrated supercooling unit 4 is located in supercooling cavity 18, integrated supercooling unit 4 is connected with liquid storage bag 8 through pipeline, saturated liquid working medium is cooled through integrated supercooling unit 4, and adjusting valve 7 is installed on the pipeline to adjust the supercooling degree of working medium.

[0021] In the embodiment, the integrated supercooling unit 4 includes two rows of tube bundles 41 extending along the radial direction of the shell 14, and the two rows of tube bundles 41 are staggered, and the angle between the center line of the two tube bundles 41 staggered up and down and the horizontal plane is β, and β is 30°. The staggered arrangement can increase the flow path of the working medium in the integrated supercooling unit 4, increase the heat exchange area, and enhance the supercooling effect. The condensed liquid working medium can be further reduced in temperature to obtain sufficient supercooling degree, avoid subsequent flashing, and ensure stable operation of the system.

[0022] Further, the liquid level gauge port 12 is arranged above the liquid storage bag 8, and the liquid level gauge port 13 is arranged below the liquid storage bag 8. The liquid level in the liquid storage bag 8 is monitored in real time by the liquid level gauge, so that the flow rate and supercooling degree of the working medium can be adjusted in time to ensure stable operation of the system. When the liquid level is too high, the flow rate of the working medium entering the integrated supercooling unit 4 can be increased by adjusting the valve 7 to ensure that the integrated supercooling unit 4 has sufficient working medium for heat exchange. When the liquid level is too low, the flow rate of the working medium flowing into the integrated supercooling unit 4 is reduced, thereby maintaining the supercooling effect of the system.

[0023] In actual engineering application, the working medium with a certain degree of superheat enters the first cavity 16 through the gas inlet 2, exchanges heat with the finned tube two 15, and the cold water flows in the finned tube two 15. The working medium flows outside the finned tube two 15 to cool the superheated steam entering the gas inlet 2. The heat exchange coefficient of the gas phase side is increased by increasing the finned tube two 15 to improve the overall heat exchange efficiency. Compared with the existing shell and tube condenser, the overall volume is reduced. After the working medium is cooled to a saturated state in the first cavity 16, the working medium enters the second cavity 17 through the gas equalization cover 3. The working medium exchanges heat with the cold water through the finned tube one 9 to condense the gaseous working medium. Since the outer wall of the finned tube one 9 is provided with liquid guide fins 91, the working medium liquid film cannot accumulate on the outer wall of the finned tube one 9. The liquid working medium quickly drips along the liquid guide fins 91. Subsequently, the condensed gaseous working medium becomes liquid and is collected in the lower liquid storage bag 8. Part of the liquid in the liquid storage bag 8 enters the integrated supercooling unit 4 through the pipeline to increase the supercooling degree of the working medium. The supercooled working medium is output through the liquid outlet pipe 6.

[0024] In the embodiment, the gas equalization cover 3 is coaxially arranged with the shell 14. The upper end of the gas equalization cover 3 is provided with two parallel gas equalization plates 31. The height of the gas equalization plate 31 gradually decreases from the gas inlet 2 along the axial direction to both sides, so that the gaseous working medium uniformly enters the first cavity 16 along the axial direction, avoids the case that the local concentration is too high, ensures that the gaseous working medium is uniformly distributed in the condenser, and thus improves the overall heat transfer efficiency of the condenser.

[0025] The condensation heat transfer characteristic surface varies along the circumferential direction of the finned tube one 9 according to the local heat transfer coefficient. Taking one side of the finned tube one 9 as an example, it is mainly divided into three regions: the impingement region 19 (0°-40°), the thermal development region 20 (40°-120°), and the desorption region 21 (120°-180°). The desorption region 21 (120°-180°) has the worst heat transfer performance and is the main cause of the heat transfer resistance. The liquid guide fin 91 is arranged in the desorption region 21 of the finned tube one 9, so that the condensing working medium at the desorption region 21 does not adhere to the tube wall, but drips through the liquid guide fin 91, thereby improving the heat transfer efficiency. In this embodiment, two liquid guide fins 91 are arranged in the desorption region 21. Specifically, the angle between the liquid guide fin 91 and the vertical direction is α, and α is 60°, so that the condensing working medium can smoothly slide down the surface of the liquid guide fin 91, avoiding accumulation on the outer wall of the finned tube one 9.

[0026] Further, the total height of the liquid guide fin 91 in the radial direction is H, H = 2 ; wherein H is the total height of the liquid guide fin 91 in the radial direction, m; t is the wall thickness of the finned tube one 9, m. It is ensured that the liquid guide fin 91 can sufficiently destroy the continuity of the liquid film and improve the overall heat transfer efficiency.

[0027] Further, the thickness of the liquid guide fin 91 gradually decreases along the radial direction, and the thickness of the liquid guide fin 91 is T, ; wherein T is the thickness of the liquid guide fin 91, m; H is the total height of the liquid guide fin 91 in the radial direction, m; t is the wall thickness of the finned tube one 9, m; h is the height of the liquid guide fin 91 at a certain radius in the radial direction, m.

[0028] The thickness of the liquid guide fin 91 changes with the height of the liquid guide fin 91 in the radial direction. This thickness change design helps the working medium droplets to flow and drip smoothly on the liquid guide fin 91, further improving the liquid film removal effect.

[0029] In this embodiment, the plurality of finned tubes one 9 are arranged in a square matrix in the second cavity 17, so that the gas-phase working medium can fully contact the finned tubes one 9 in the second cavity 17, improving the condensation efficiency. The square matrix arrangement makes the spacing between the finned tubes one 9 uniform, which is conducive to the uniform distribution and flow of the gas-phase working medium, avoiding the occurrence of local flow dead angles or excessively fast or slow flow rates, thereby ensuring the stability and efficiency of the condensation process. At the same time, this arrangement also facilitates the installation and maintenance of the finned tubes one 9, reducing the manufacturing cost and operating cost of the equipment. In actual application, the arrangement and spacing of the finned tubes one 9 can be optimized according to specific requirements and working conditions to achieve the best condensation effect.

[0030] In order not to affect the equalizing effect of the equalizing cover 3, the finned tube two 15 is arranged in a ring array with the axis of the shell 14 as the center in the first cavity 16. If the finned tube two 15 is arranged too densely, the equalizing effect of the equalizing cover 3 will be affected, and if the finned tube two 15 is arranged too sparsely, the overheated steam cannot be cooled to the saturated state completely, so the spacing of the ring array has certain influence on the heat exchange effect of the present application. The spacing between adjacent finned tube two 15 is , ; In the formula: D1 - the outer diameter of the shell 14, m; D2 - the outer diameter of the equalizing cover 3, m; S - the spacing of the ring array, m; T1 - the saturation temperature of the working medium, K; T2 - the temperature of the working medium inlet, K. Reasonable spacing design can ensure sufficient heat exchange of the working medium in the first cavity 16 and uniform flow field distribution.

[0031] Further, the maximum radial cross-sectional area of the fin on the finned tube two 15 is 5-8 times the cross-sectional area of the outer diameter of the tube, so as to enhance the heat exchange effect. The inner diameter of the finned tube two 15 is , ; In the formula: D3 - the inner diameter of the finned tube two 15, m; D1 - the outer diameter of the shell 14, m; D2 - the outer diameter of the equalizing cover 3, m; h1 - the convective heat transfer coefficient inside the tube, W / m 2 ·K; h2 - the convective heat transfer coefficient outside the tube, W / m 2 ·K. The heat exchange performance of the finned tube two 15 can be optimized, and the heat transfer efficiency of the overall condenser is improved.

[0032] In summary, the application realizes efficient gas-liquid two-phase heat exchange and liquid film automatic removal function, through the synergistic effect of the air equalizing cover 3, the finned tube one 9 and the finned tube two 15, the uniform distribution and sufficient heat exchange of the working medium in the condenser are ensured. The inclined design of the air equalizing plate 31 on the air equalizing cover 3 effectively avoids the local concentration of the gas-phase working medium, and improves the heat transfer efficiency; the liquid guide fin 91 on the finned tube one 9 destroys the continuity of the liquid film, realizes the rapid dripping of the liquid droplets, prevents the accumulation and thickening of the liquid film, and improves the heat transfer efficiency; the annular arrangement and reasonable spacing design of the finned tube two 15 further optimize the heat exchange path and flow field distribution of the working medium. The introduction of the integrated supercooling unit 4 makes the condensed liquid working medium further reduce the temperature and obtain sufficient supercooling degree, thereby avoiding the subsequent flash phenomenon and ensuring the stable operation of the system. Therefore, the application not only improves the overall heat transfer efficiency of the condenser, but also reduces the manufacturing cost and operation cost of the equipment.

[0033] The above only describes the preferred embodiments of the application and is not intended to limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A shell-and-tube condenser capable of automatically removing liquid film, comprising a shell (14), one end of the shell (14) being provided with a cold water inlet (5), the other end being provided with a cold water outlet (1), the upper end of the shell (14) being provided with an air inlet (2), and the lower end of the shell (14) being connected with a liquid outlet pipe (6), characterized in that, The shell (14) is provided with a uniform gas cover (3), a finned tube one (9) and a finned tube two (15), the uniform gas cover (3) is provided with a plurality of uniform gas holes, the uniform gas cover (3) divides the inner cavity of the shell (14) into a first cavity (16) and a second cavity (17), the first cavity (16) is provided with the finned tube two (15), the second cavity (17) is provided with the finned tube one (9), the outer wall of the finned tube one (9) is provided with a liquid guide fin (91).

2. The shell and tube condenser automatically removing liquid film according to claim 1, characterized in that, The lower end of the shell (14) is provided with a liquid storage bag (8), the shell (14) is provided with a partition plate (11) and an integrated supercooling unit (4), the partition plate (11) is located at one end close to the cold water inlet (5), the partition plate (11) cooperates with the inner wall of the shell (14) to form a supercooling cavity (18), the integrated supercooling unit (4) is located in the supercooling cavity (18), and the integrated supercooling unit (4) is connected with the liquid storage bag (8).

3. The shell and tube condenser automatically removing liquid film according to claim 1, characterized in that, The uniform gas cover (3) is coaxially arranged with the shell (14), the upper end of the uniform gas cover (3) is provided with two parallel uniform gas plates (31), and the height of the uniform gas plate (31) gradually decreases from the air inlet (2) to both sides along the axial direction.

4. The shell and tube condenser automatically removing liquid film according to claim 1, characterized in that, A plurality of the finned tube one (9) is arranged in a square matrix in the second cavity (17).

5. The shell-and-tube condenser automatically removing liquid film according to claim 1 or 4, characterized in that, Each of the finned tube one (9) is provided with two liquid guide fins (91), and the liquid guide fins (91) are arranged in the separation zone (21) of the finned tube one (9).

6. The shell and tube condenser automatically removing liquid film according to claim 5, characterized in that, The total height of the liquid guiding fin (91) in the radial direction is H, ; H - total height of the liquid guiding fin (91) in the radial direction, m - wall thickness of the finned tube one (9), m.

7. The shell and tube condenser automatically removing liquid film according to claim 6, characterized in that, The thickness of the liquid guide fin (91) gradually decreases in the radial direction, and the thickness of the liquid guide fin (91) is T, ; In the formula: T is the thickness of the liquid guide fin (91), m; H is the total height of the liquid guide fin (91) in the radial direction, m; — wall thickness of the finned tube (9), m; h— height of the liquid guide fin (91) at a certain radius in the radial direction, m.

8. The shell and tube condenser automatically removing liquid film according to claim 1, characterized in that, The finned tube two (15) is arranged in a ring in the first cavity (16), and the distance between adjacent finned tube two (15) is S, ; In the formulae: - the outer diameter of the housing (14), m; - the outer diameter of the equalizing hood (3), m; - pitch of the annular array, m; Ts - saturation temperature of the working fluid, K; - temperature of the working fluid at the inlet, K.

9. The shell and tube condenser automatically removing liquid film according to claim 8, characterized in that, The inner diameter of the finned tube two (15) is , ; In the formulae: - inner diameter of the finned tube two (15), m; - outer diameter of the housing (14), m; - the outer diameter of the uniform gas cover (3), m; - the convective heat transfer coefficient inside the tube, W / m 2 K; - convection heat transfer coefficient outside the tube, W / m 2 • K.

10. The shell and tube condenser automatically removing liquid film according to claim 2, characterized in that, The integrated supercooling unit (4) comprises two rows of tube bundles (41), the two rows of tube bundles (41) extend along the radial direction of the shell (14), and the two rows of tube bundles (41) are staggered.

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