Axial variable space flue gas condenser and preparation method thereof

Abstract

The invention provides an axial variable-space flue gas condenser and a preparation method thereof, and relates to the technical field of flue gas condensers, and the flue gas condenser is characterized in that a shell is provided with a flue gas inlet end and a flue gas outlet end at the two ends in the extending direction of the shell respectively; a guide space is formed in the guide cylinder, and the two ends of the guide cylinder in the axial direction are mounted on the inner wall of the shell; the heat exchange tube bundle is arranged in the flow guide space and comprises a plurality of heat exchange tubes, condensate circulates in the heat exchange tubes, high-temperature flue gas entering from the flue gas inlet end circulates between the heat exchange tubes and the flow guide cylinder, and the condensed high-temperature flue gas is discharged from the flue gas outlet end; the heat exchange tubes are of a twisted spiral structure in the axial direction of the heat exchange tubes so as to form the heat exchange tube bundle with the three-dimensional variable space, and the spiral pitch of the twisted spiral structure of the heat exchange tube close to one side of the smoke inlet end is smaller than that of the twisted spiral structure of the heat exchange tube close to one side of the smoke outlet end. The flue gas condenser is good in heat exchange effect and ash deposition prevention effect.

Description

Technical Field

[0001] The present application relates to the technical field of flue gas condensers, and in particular to an axial variable space flue gas condenser and a preparation method thereof. Background Art

[0002] In industrial production, a large amount of high-temperature flue gas is often generated. These high-temperature flue gases contain a large amount of heat energy. If they are directly discharged into the atmosphere, it will not only cause energy waste, but also cause environmental pollution. Therefore, it is necessary to condense the high-temperature flue gas to recover the heat energy and reduce environmental pollution. Traditional flue gas condensers usually use straight tube heat exchange tubes, which have low heat exchange efficiency and are prone to dust accumulation, affecting the heat exchange effect. Summary of the invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, the present application aims to provide an axially variable space flue gas condenser and a preparation method thereof, aiming to improve the heat exchange effect of the condenser.

[0004] In a first aspect, the present application proposes an axial variable space flue gas condenser, comprising: A shell, wherein the shell has a first space therein, and the shell has a smoke inlet end and a smoke outlet end at two ends along its extension direction respectively; A flow guide tube, wherein the flow guide tube has a flow guide space therein, the flow guide tube is arranged in the first space, and both ends along the axial direction of the flow guide tube are mounted on the inner wall of the shell; A heat exchange tube bundle, wherein the heat exchange tube bundle is arranged in the guide space, the heat exchange tube bundle comprises a plurality of heat exchange tubes, condensate flows in the heat exchange tubes, high-temperature flue gas entering from the flue gas inlet end flows between the heat exchange tubes and the guide tube, and the condensed high-temperature flue gas is discharged from the flue gas outlet end; The heat exchange tube is in a twisted spiral structure along its axial direction to form a heat exchange tube bundle with a three-dimensional variable space, wherein the spiral pitch of the heat exchange tube close to the flue gas inlet end is smaller than the spiral pitch of the heat exchange tube close to the flue gas outlet end.

[0005] According to the technical solution provided in the present application, the portion of the heat exchange tube close to the flue gas inlet end is the inlet section, the portion of the heat exchange tube close to the flue gas outlet end is the outlet section, and the portion of the heat exchange tube located between the inlet section and the outlet section is the middle section; the spiral pitch of the inlet section and the outlet section remains unchanged, and the spiral pitch of the twisted spiral structure in the middle section gradually increases in the direction from the inlet section to the outlet section.

[0006] According to the technical solution provided in the present application, the spiral pitch change rate of the intermediate section is smaller than the relative change ratio of the spiral pitch between the inlet section and the outlet section.

[0007] According to the technical solution provided in the present application, the flow directions of the high-temperature flue gas and the condensate are opposite.

[0008] According to the technical solution provided in the present application, the guide tube is provided with an inlet tube sheet and an outlet tube sheet at both ends along the axial direction thereof, respectively, and the inlet tube sheet and the outlet tube sheet respectively have a plurality of tube holes adapted to the heat exchange tubes, the inlet section of the heat exchange tube passes through the tube hole of the inlet tube sheet, and the outlet section of the heat exchange tube passes through the tube hole of the outlet tube sheet.

[0009] According to the technical solution provided in the present application, all the heat exchange tubes are arranged in parallel or staggered. When staggered, the staggered arrangement angle of any two adjacent heat exchange tubes is the same, and the staggered arrangement angle is the angle between the extension line of the heat exchange tube and the extension line of the axis of the inlet tube sheet.

[0010] In a second aspect, the present application proposes a method for preparing an axially variable space flue gas condenser, which is used to prepare a heat exchange tube bundle in the axially variable space flue gas condenser as described above, comprising the following steps: If the initial condenser does not meet the heat exchange requirements of the target unit high-temperature flue gas, a heat exchange compensation is obtained, wherein the heat exchange compensation is the difference between the target heat exchange specified by the target unit and the actual heat exchange of the initial condenser; the initial condenser has an initial heat exchange tube; According to the heat exchange compensation, a compensation area of ​​each heat exchange tube in the heat exchange tube bundle of the updated condenser is obtained, wherein the compensation area represents an effective heat exchange area that needs to be increased on each of the initial heat exchange tubes in order to achieve the heat exchange compensation; Respectively obtaining the first segmented heat exchange requirements of the outlet section and the inlet section of the updated heat exchange tube, and allocating the compensation area according to the first segmented heat exchange requirements of the outlet section and the inlet section to obtain a first spiral pitch of the inlet section and a second spiral pitch of the outlet section; Each of the heat exchange tubes is prepared with the first spiral pitch and the second spiral pitch, thereby obtaining the heat exchange tube bundle.

[0011] According to the technical solution provided by the present application, the compensation area is allocated according to the first segmented heat exchange requirements of the outlet section and the inlet section to obtain the first spiral pitch of the inlet section and the second spiral pitch of the outlet section, specifically comprising the following steps: Allocating the compensation area according to the ratio of the first segmented heat exchange requirements of the inlet section and the outlet section to obtain a first compensation area of ​​the inlet section and a second compensation area of ​​the outlet section; The first spiral pitch is obtained according to the first compensation area, and the second spiral pitch is obtained according to the second compensation area.

[0012] According to the technical solution provided by the present application, after allocating the compensation area according to the ratio of the first segmented heat exchange requirements of the inlet section and the outlet section to obtain the first compensation area of ​​the inlet section and the second compensation area of ​​the outlet section, the following steps are also included: According to the structural dimensions of the initial condenser, a first reference length and a reference outer diameter are obtained; wherein the first reference length is the length of a center line connecting a tube hole on the inlet tube sheet and a tube hole on the outlet tube sheet corresponding thereto, and the reference outer diameter is the outer diameter of a heat exchange tube of the initial condenser; determining whether the first reference length and the reference outer diameter are sufficient to configure the first compensation area; The method of obtaining the first spiral pitch according to the first compensation area and obtaining the second spiral pitch according to the second compensation area specifically comprises the following steps: If so, the first spiral pitch is obtained according to the first compensation area, and the second spiral pitch is obtained according to the second compensation area.

[0013] According to the technical solution provided by the present application, after determining whether the first reference length and the reference outer diameter are sufficient to configure the first compensation area, the following steps are also included: If not, obtain a second reference length set, the second reference length set including a plurality of second reference lengths, the second reference length being the length of a center line connecting a tube hole of the inlet tube sheet and a tube hole offset therewith on the outlet tube sheet, the second reference length being greater than the first reference length; If there is a second reference length in the second reference length set that is sufficient to configure the first compensation area, a third spiral pitch is obtained according to the first compensation area, and a fourth spiral pitch is obtained according to the second compensation area.

[0014] Compared with the prior art, the beneficial effects of this application are: 1. The axial variable space flue gas condenser of the present invention has a heat exchange tube with a twisted spiral structure along the axial direction, forming a heat exchange tube bundle with a three-dimensional variable space. Compared with the traditional straight tube heat exchange tube, the heat exchange area is increased to improve the heat exchange efficiency. In addition, the spiral pitch of the twisted spiral structure of the heat exchange tube on the side close to the flue gas inlet end is smaller than the spiral pitch of the heat exchange tube on the side close to the flue gas outlet end, so that the heat exchange area close to the flue gas inlet end is larger, meeting the demand for rapid cooling of high-temperature flue gas; the heat exchange area close to the flue gas outlet end is smaller, avoiding the waste of heat exchange area.

[0015] 2. The heat exchange tube with a twisted spiral structure makes the flue gas rotate during the flow process, reducing the possibility of ash accumulation. Due to the change in the spiral pitch of the heat exchange tube, the smoke passage in the area with a smaller spiral pitch is relatively narrow, the resistance encountered by the smoke when passing through increases, and the flow rate increases. When the fluid flows through the narrow channel, the speed will increase to maintain the continuity of the flow. The smoke passage in the area with a larger spiral pitch becomes wider, and the smoke flow rate decreases accordingly. This speed change along the flow direction of the smoke makes the flow state of the smoke in the entire heat exchange tube bundle more complicated, which is not conducive to the stable deposition of ash particles. In the area with a smaller pitch, the fast-flowing smoke will produce a strong airflow impact and shear force, and also have a scouring effect on the ash particles that have been deposited on the tube wall, making it difficult for them to continue to adhere, thereby achieving an anti-ash deposition effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of the axial variable space flue gas condenser provided in this application; Figure 2 A schematic diagram of the structure of the parallel arrangement of heat exchange tubes in the axial variable space flue gas condenser provided in the present application; Figure 3 A schematic diagram of the structure of the staggered arrangement of heat exchange tubes in the axially variable space flue gas condenser provided in the present application; Figure 4 A flow chart of the steps of the method for preparing the axially variable space flue gas condenser provided in this application.

[0017] The text labels shown in the figure represent: 1. Shell; 2. Draft tube; 3. Inlet tube sheet; 4. Tube hole; 5. Heat exchange tube bundle; 6. Outlet tube sheet; 7. Inlet section; 8. Middle section; 9. Outlet section; 10. Heat exchange tube. DETAILED DESCRIPTION

[0018] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant inventions, rather than to limit the inventions. It should also be noted that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0019] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0020] Example 1 As mentioned in the background technology, in view of the problems in the prior art, this application proposes an axial variable space flue gas condenser, please refer to Figure 1 As shown, including: A shell 1, wherein the shell 1 has a first space therein, and the shell 1 has a smoke inlet end and a smoke outlet end at two ends along its extension direction respectively; A flow guide tube 2, wherein the flow guide tube 2 has a flow guide space therein, the flow guide tube 2 is disposed in the first space, and both ends of the flow guide tube 2 along the axial direction are mounted on the inner wall of the housing 1; Specifically, the shell 1 is made of high temperature resistant and corrosion resistant material to ensure that it can withstand the effects of high temperature flue gas. A first space is formed inside the shell 1, and the shape can be designed to be cylindrical, rectangular, etc. according to actual needs. The two ends of the guide tube 2 are respectively determined as the flue gas inlet end and the flue gas outlet end. The two ends of the shell 1 can be designed as flange connections so that the external pipeline is connected to the guide tube 2. The guide tube 2 is made of a material with good thermal conductivity. The internal guide space is used to guide the flow direction of the high temperature flue gas. The two ends along the axial direction are firmly mounted on the inner wall of the shell 1 by welding, bolting, etc. to ensure that no displacement occurs during operation.

[0021] A heat exchange tube bundle 5, wherein the heat exchange tube bundle 5 is arranged in the guide space, and the heat exchange tube bundle 5 includes a plurality of heat exchange tubes 10, wherein condensate flows in the heat exchange tubes 10, and high-temperature flue gas entering from the flue gas inlet end flows between the heat exchange tubes 10 and the guide tube 2, and the high-temperature flue gas after condensation is discharged from the flue gas outlet end; Specifically, the flue gas inlet is usually connected to the equipment or pipeline that generates high-temperature flue gas in the industrial production process. For example, in a thermal power plant, it can be connected to the exhaust pipe of the boiler. The high-temperature flue gas enters the space between the guide tube 2 and the heat exchange tube 10 from the flue gas inlet. The guide tube 2 at the flue gas outlet is connected to the subsequent flue gas treatment equipment or discharge pipeline so that the low-temperature flue gas flowing through the guide tube 2 and heat exchanged by the condensate in the heat exchange tube 10 is subjected to the next step of treatment. For example, it can be connected to a dust collector, desulfurization and denitrification equipment, etc. to meet environmental protection requirements. The condensate enters the heat exchange tube 10 from the flue gas outlet through an external condensate circulation system and is then discharged from the flue gas inlet. The condensate circulation system may include components such as a pump, a liquid storage tank, and a pipeline. The pump extracts the condensate from the liquid storage tank and transports it to the condensate inlet (at the flue gas outlet) of the heat exchange tube 10 through a pipeline. The condensate flows in the heat exchange tube 10, exchanges heat with the high-temperature flue gas outside the tube, and then flows out from the condensate outlet of the heat exchange tube 10 (at the flue gas inlet end) and returns to the liquid storage tank for cooling or recycling.

[0022] The heat exchange tube 10 is in a twisted spiral structure along its axial direction to form the heat exchange tube bundle 5 with a three-dimensional variable space, wherein the spiral pitch of the heat exchange tube 10 near the flue gas inlet end is smaller than the spiral pitch of the heat exchange tube 10 near the flue gas outlet end, and the spiral pitch is the distance that the spiral line of the twisted spiral structure advances per turn along the axial direction of the heat exchange tube 10. The heat exchange tubes 10 in the heat exchange tube bundle 5 can be arranged regularly in parallel or staggered.

[0023] Working principle: When the high-temperature flue gas enters the condenser from the flue gas inlet, it first enters the space between the guide tube 2 and the heat exchange tube 10. Since the heat exchange tube 10 has a twisted spiral structure, the heat exchange area is increased, so that the high-temperature flue gas can fully contact the heat exchange tube 10. During the flow of the high-temperature flue gas, the heat is transferred to the condensate in the heat exchange tube 10, and its own temperature is reduced. After the condensate absorbs heat, the temperature rises, and heat exchange is achieved. The spiral pitch of the heat exchange tube 10 on the side close to the flue gas inlet is smaller, which enables the high-temperature flue gas to exchange heat more closely with the condensate at the initial stage of entering the condenser, thereby improving the heat exchange efficiency. As the high-temperature flue gas flows toward the flue gas outlet, the spiral pitch of the heat exchange tube 10 gradually increases, providing a larger space for the flow of the flue gas and reducing the flow resistance of the flue gas.

[0024] In a preferred embodiment, the portion of the heat exchange tube 10 close to the flue gas inlet end is the inlet section 7, the portion of the heat exchange tube 10 close to the flue gas outlet end is the outlet section 9, and the portion of the heat exchange tube 10 located between the inlet section 7 and the outlet section 9 is the middle section 8; the spiral pitch of the inlet section 7 and the outlet section 8 remains unchanged, and the spiral pitch of the twisted spiral structure in the middle section 8 gradually increases in the direction from the inlet section 7 to the outlet section 9.

[0025] Specifically, in the actual manufacturing process, each section can be accurately divided by measuring the distance or setting marks. When manufacturing the twisted spiral structure of the heat exchange tube 10, the spiral pitch of the middle section 8 is gradually increased by gradually increasing the distance of advancement of the spiral line per turn from the inlet section 7 to the outlet section 9. The parameters of the processing equipment, such as the rotation speed and the feed speed, can be precisely controlled to ensure that the change in the spiral pitch meets the requirements. For example, a dedicated spiral tube processing machine tool is used to process according to a preset pitch change curve to achieve the change in the spiral pitch.

[0026] In a preferred embodiment, the rate of change of the helical pitch of the intermediate section 8 is smaller than the relative rate of change of the helical pitch between the inlet section 7 and the outlet section 9 .

[0027] Specifically, the spiral pitch change rate of the middle section 8 remains consistent along the axial direction, and the spiral pitch change rate of the middle section 8 is (spiral pitch of the latter position - spiral pitch of the former position) / axial distance between the two positions, and the relative change rate of the spiral pitch between the inlet section 7 and the outlet section 9 is (spiral pitch of the outlet section - spiral pitch of the inlet section) / spiral pitch of the inlet section.

[0028] Specifically, the relative change rate of the spiral pitch between the inlet section 7 and the outlet section 9 reflects the degree of difference in the structures at both ends. The change rate of the spiral pitch of the middle section is less than this ratio, which means that the structural change of the middle section 8 is relatively gentle. In this way, the middle section 8 can play a "buffer" and "stabilizing" role in the heat exchange process. For example, when the flue gas enters the middle section 8 from the inlet section, the flue gas flow will not be turbulent or the heat exchange will not be uneven due to excessive structural changes. Under the relatively stable spiral pitch environment of the middle section 8, heat can be transferred more evenly and stably between the heat exchange tubes 10, thereby improving the overall heat exchange efficiency. In addition, by limiting the change rate of the middle section 8, the thermal stress concentration and mechanical stress caused by structural changes can also be reduced. If the spiral pitch of the middle section 8 changes too drastically, the heat exchange tube 10 will cause fatigue damage during operation due to uneven thermal expansion or large fluid force. A relatively small spiral pitch change rate helps to maintain the structural stability of the heat exchange tube 10, thereby extending the service life of the condenser.

[0029] In a preferred embodiment, the high-temperature flue gas and the condensate flow in opposite directions.

[0030] Specifically, the counter-flow can make all parts of the entire heat exchange tube bundle 5 fully exert the heat exchange effect. If it is a co-flow, in the later stage of the heat exchange process, when the flue gas and the condensate temperature are close, the heat exchange driving force will decrease, resulting in part of the heat exchange area cannot be effectively utilized. The counter-flow can avoid this situation, make the heat exchange more sufficient, and improve the heat exchange efficiency of the condenser.

[0031] In a preferred embodiment, please refer to Figure 2 and Figure 3 As shown, the guide tube 2 is provided with an inlet tube sheet 3 and an outlet tube sheet 6 at both ends along the axial direction thereof, respectively. The inlet tube sheet 3 and the outlet tube sheet 6 respectively have a plurality of tube holes 4 adapted to the heat exchange tube 10, the inlet section 7 of the heat exchange tube 10 penetrates the tube hole 4 of the inlet tube sheet 3, and the outlet section 9 of the heat exchange tube 10 penetrates the tube hole 4 of the outlet tube sheet 6.

[0032] Specifically, the tube sheet provides a positioning reference for the installation of the heat exchange tubes 10, making the installation of the heat exchange tubes 10 more convenient and quick. When the heat exchange tubes 10 need to be evenly arranged in parallel, the heat exchange tubes 10 in the heat exchange tube bundle 5 can be arranged in parallel or in a staggered arrangement. The staggered arrangement will make the flow path of the fluid in the heat exchange tube bundle 5 more complicated. Compared with the parallel arrangement, the fluid will generate more turbulence and vortices when flowing through the staggered arrangement of the heat exchange tubes 10. This complex flow state can destroy the boundary layer of the fluid, making it easier for heat to be transferred from the fluid to the wall of the heat exchange tube 10.

[0033] Specifically, when arranged in parallel, Figure 2 As shown, on the outlet tube sheet 6 and the inlet tube sheet 3, the center lines of the tube holes 4 on the left and right sides of each heat exchange tube 10 are parallel, and each heat exchange tube 10 is perpendicular to the inlet tube sheet 3 or the outlet tube sheet 6. When the staggered arrangement is performed, as shown in FIG. Figure 3As shown, the tube holes 4 on the outlet tube sheet 6 and the inlet tube sheet 3 need to be adaptively arranged according to the staggered arrangement angle. For example, the tube holes 4 on the inlet tube sheet 3 and the outlet tube sheet 6 can be circumferentially distributed in an array with 9, and the angle between every two adjacent tube holes 4 is 360 / 9=40 degrees. If the tube holes 4 on the inlet tube sheet 3 are numbered as inlet hole 1, inlet hole 2, inlet hole 3, inlet hole 4, inlet hole 5, inlet hole 6, inlet hole 7, inlet hole 8, and inlet hole 9, and the tube holes 4 on the outlet tube sheet 6 are numbered as outlet hole 1, outlet hole 2, outlet hole 4, outlet hole 5, outlet hole 6, outlet hole 7, outlet hole 8, and outlet hole 9, 3 holes, 4 holes, 5 holes, 6 holes, 7 holes, 8 holes, and 9 holes. Therefore, for the staggered arrangement, the heat exchange tube 10 is inserted in the following manner: Method 1: 1 hole inlet to 2 holes outlet, 2 holes inlet to 3 holes outlet, 4 holes inlet to 5 holes outlet...9 holes inlet to 1 hole outlet. It can also be Method 2: 1 hole inlet to 3 holes outlet, 2 holes inlet to 4 holes outlet, 3 holes inlet to 5 holes outlet, 4 holes inlet to 6 holes outlet...9 holes inlet to 2 holes outlet. It can also be other staggered methods, in which the staggered angle of Method 1 is smaller than that of Method 2.

[0034] In a preferred embodiment, all the heat exchange tubes 10 are arranged in parallel or staggered. When staggered, the staggered arrangement angles of any two adjacent heat exchange tubes 10 are the same, and the staggered arrangement angle is the angle between the extension line of the heat exchange tube 10 and the extension line of the axis of the inlet tube sheet 3.

[0035] Specifically, the existence of the staggered arrangement angle makes the spatial layout between adjacent heat exchange tubes 10 more complicated. When the high-temperature flue gas flows between the guide tube 2 and the heat exchange tube 10, this complex layout will cause more disturbances in the flue gas. At the same time, the staggered arrangement angles of every two adjacent heat exchange tubes 10 are the same, which means that when all the heat exchange tubes 10 are staggered, their inclination angles relative to the inlet tube sheet 3 are consistent. Such a regular arrangement helps to ensure the structural regularity of the entire heat exchange tube bundle 5 and the orderliness of the fluid flow. The disturbance of the flue gas increases its contact opportunities with the surface of the heat exchange tube 10, so that heat can be more effectively transferred from the flue gas to the condensate in the heat exchange tube 10. At the same time, if the heat exchange tubes 10 are arranged neatly, when the condensate or flue gas flow rate is low, some flow dead zones may be formed between adjacent heat exchange tubes 10, that is, areas where the flue gas flows slowly or even stagnates. The heat exchange tubes 10 with staggered arrangement angles can avoid this situation and ensure that the flue gas flows evenly in the entire guide space.

[0036] Example 2 Based on Example 1, this example proposes a method for preparing an axially variable space flue gas condenser, which is used to prepare the heat exchange tube bundle 5 in the axially variable space flue gas condenser as described above. Figure 4 As shown, the following steps are included: S1. If the initial condenser does not meet the heat exchange requirement of the target unit high-temperature flue gas, obtain heat exchange compensation, the heat exchange compensation being the difference between the target heat exchange specified by the target unit and the actual heat exchange of the initial condenser; the initial condenser has an initial heat exchange tube; Specifically, whether the initial condenser meets the heat exchange demand of the target unit of high-temperature flue gas is judged by the target temperature difference and the target temperature at the outlet. Specifically, when the actual temperature difference of the initial condenser is less than the target temperature difference and the actual temperature at the outlet is greater than the target temperature at the outlet, it is determined that the initial condenser does not meet the heat exchange demand of the target unit of high-temperature flue gas.

[0037] Here is a usage scenario. In a thermal power plant (target unit), an initial condenser is installed to cool the high-temperature flue gas generated by the thermal power plant. The heat exchange requirement specified by this target unit is to reduce the temperature of the high-temperature flue gas from 500 degrees at the inlet to 300 degrees when it reaches the outlet through condensate heat exchange. If the existing initial condenser of the thermal power plant can only reduce the outlet temperature to above 300 degrees, for example, 350 degrees, it is determined that the initial condenser does not meet the heat exchange requirements of the high-temperature flue gas of the target unit. The target heat exchange rate is determined by the thermal power plant according to the policy, and the actual heat exchange rate is determined by the formula Get, where C is the specific heat capacity of flue gas, M is the unit flow rate of flue gas, is the inlet and outlet temperature difference of the initial condenser in actual operation. For example, the target heat exchange 2000KW, actual heat exchange capacity 1500KW, heat exchange compensation It is 500KW.

[0038] S2. According to the heat exchange compensation, a compensation area of ​​each heat exchange tube 10 in the heat exchange tube bundle 5 of the updated condenser is obtained, wherein the compensation area represents an effective heat exchange area that needs to be increased on each of the initial heat exchange tubes 10 in order to achieve the heat exchange compensation; Specifically, this scheme uses the structural dimensions of the initial condenser as a reference to transform or prepare the updated condenser to meet the new heat exchange requirements of the thermal power plant. If the shell 1 and the guide tube 2 of the initial condenser are intact, the heat exchange tube bundle 5 proposed in this scheme can be replaced to achieve the purpose of meeting the heat exchange requirements, avoiding large-scale transformation of the entire condenser infrastructure, reducing costs and construction difficulties. If the shell 1 and the guide tube 2 of the initial condenser are worn and damaged, a complete condenser needs to be manufactured. At this time, it is also necessary to ensure that the structural dimensions of the updated condenser are equivalent to those of the initial condenser, so that it can adapt to the installation site of the initial condenser, and the original installation site and the pipes and ancillary equipment connected thereto can be used. Regardless of which of the above methods is used, this scheme defaults to the number n of heat exchange tubes 10 in the heat exchange tube bundle 5 of the replaced condenser to be consistent with the initial condenser, and the outer diameter of the heat exchange tube 10 and the inner diameter of the heat exchange tube 10 are also the same to ensure the compatibility and continuity of the entire system. It should be noted that the subsequent calculation of the compensation area and the modification of the heat exchange tube 10 (such as changing the spiral pitch, etc.) all take into account the heat exchange compensation requirements based on these fixed parameters.

[0039] Specifically, the heat exchange compensation is output to the compensation area model to obtain the compensation area of ​​each heat exchange tube 10, wherein the compensation area model is obtained through neural network training, and its input is the heat exchange compensation and the structural parameters of the initial heat exchange tube, and the output is the compensation area. Exemplarily, the compensation area is 0.27 square meters.

[0040] S3, respectively obtaining the first segmented heat exchange requirements of the outlet section 9 and the inlet section 7 of the updated heat exchange tube 10, and allocating the compensation area according to the first segmented heat exchange requirements of the outlet section 9 and the inlet section 7 to obtain a first spiral pitch of the inlet section 7 and a second spiral pitch of the outlet section 9; Specifically, obtain the historical operation database of multiple condensers in multiple thermal power plants to find out whether there is a reference condenser that matches the target heat exchange rate of the thermal power plant. If so, use the reference heat exchange rate of the reference outlet section 9 of the heat exchange tube 10 of the reference condenser as the first segment heat exchange requirement of the outlet section 9 of the updated heat exchange tube 10, and use the reference heat exchange rate of the reference inlet section 7 of the heat exchange tube 10 of the reference condenser as the first segment heat exchange requirement of the inlet section 7 of the updated heat exchange tube 10. The reference heat exchange rate of the reference condenser is recorded over a long period of time by temperature sensors installed at different positions of the heat exchange tube 10 of the reference condenser (for example, sensors set at specific positions near the inlet and outlet along the axial direction of the heat exchange tube 10). Exemplarily, the first temperature drop amplitude The second temperature drop is 100 degrees Celsius. is 50 degrees Celsius.

[0041] Further, the compensation area is allocated according to the first segmented heat exchange requirements of the outlet section 9 and the inlet section 7 to obtain the first spiral pitch of the inlet section 7 and the second spiral pitch of the outlet section 9, specifically comprising the following steps: Allocate the compensation area according to the ratio of the first segmented heat exchange requirements of the inlet section 7 and the outlet section 9 to obtain a first compensation area of ​​the inlet section 7 and a second compensation area of ​​the outlet section 9; Obtain the first spiral pitch according to the first compensation area, and obtain the second spiral pitch according to the second compensation area; Specifically, the heat exchange requirement of the first section of the inlet section 7 is , the heat exchange requirement of the first section of the outlet section 9 is Therefore, the proportionality coefficient K1 of the inlet section 7 is , the proportional coefficient K2 of the outlet section 9 is From the above data, we can get that K1 is 2 / 3 and K2 is 1 / 3. Then, the first compensation area is the product of 0.27 and 2 / 3, which is 0.18, and the second compensation area is the product of 0.27 and 1 / 3, which is 0.09.

[0042] Furthermore, after allocating the compensation area according to the ratio of the first segmented heat exchange requirements of the inlet section 7 and the outlet section 9 to obtain the first compensation area of ​​the inlet section 7 and the second compensation area of ​​the outlet section 9, the method further includes the following steps: According to the structural dimensions of the initial condenser, a first reference length and a reference outer diameter are obtained; wherein the first reference length is the length of the center line connecting the tube hole 4 of the inlet tube sheet 3 and the corresponding tube hole 4 on the outlet tube sheet 6, and the reference outer diameter is the outer diameter of the heat exchange tube 10 of the initial condenser; determining whether the first reference length and the reference outer diameter are sufficient to configure the first compensation area; Specifically, since the first compensation area of ​​the inlet section 7 is definitely larger than the second compensation area of ​​the outlet section 9, and the inlet section 7 and the outlet section 9 have the same length and outer diameter, if the inlet section 7 is sufficient to configure the first compensation area, then the outlet section 9 is also sufficient to configure it. Therefore, in this embodiment, only the configuration satisfaction of the inlet section 7 is determined.

[0043] Specifically, the heat exchange tube 10 with the first reference length and reference outer diameter is used as the reference heat exchange tube. The reference heat exchange tube is a straight tube. Based on the pressure drop and process requirements, the inlet section 7 of the reference heat exchange tube can be configured as an optional area range of a spiral tube. If the first compensation area is within the optional area range, it is determined that the first reference length and reference outer diameter are sufficient to configure the first compensation area.

[0044] Specifically, based on the pressure drop (determine the structural parameter range of the spiral heat exchange tube without exceeding the pressure drop, and then obtain the corresponding first heat exchange area range), based on process requirements (spiral processing accuracy, material machinability, etc. In actual production, the size and structure of the spiral heat exchange tube that can be manufactured have a certain range), the corresponding second heat exchange area range is obtained, and the intersection of the first heat exchange area range and the second heat exchange area range is the optional area range.

[0045] The first spiral pitch is obtained according to the first compensation area, and the second spiral pitch is obtained according to the second compensation area.

[0046] The method of obtaining the first spiral pitch according to the first compensation area and obtaining the second spiral pitch according to the second compensation area specifically comprises the following steps: If so, the first spiral pitch is obtained according to the first compensation area, and the second spiral pitch is obtained according to the second compensation area.

[0047] Specifically, if it is determined that the first reference length and the reference outer diameter are sufficient to configure the first compensation area, the length of the inlet section 7, the reference inner diameter and the reference outer diameter (all the same as the heat exchange tube of the initial condenser), and the first compensation area are input into the pitch calculation model to obtain the first spiral pitch, and the second spiral pitch is obtained similarly, wherein the pitch calculation model is obtained by neural network training, and its input is the local section length, inner diameter, outer diameter, and compensation area of ​​the spiral structure of the heat exchange tube 10, and the output is the corresponding spiral pitch.

[0048] S4. Prepare each of the heat exchange tubes 10 with the first spiral pitch and the second spiral pitch, thereby obtaining the heat exchange tube bundle 5.

[0049] In a preferred embodiment, after determining whether the first reference length and the reference outer diameter are sufficient to configure the first compensation area, the following steps are also included: If not, obtain a second reference length set, the second reference length set including a plurality of second reference lengths, the second reference length being the length of a center line connecting the tube hole 4 of the inlet tube sheet 3 and the tube hole 4 misaligned therewith on the outlet tube sheet 6, the second reference length being greater than the first reference length; Specifically, if it is determined that the first reference length and the reference outer diameter are insufficient to configure the first compensation area, it means that if the heat exchange tube 10 of the replaced condenser is to be consistent with the initial heat exchange tube length of the initial condenser, it is impossible to configure the spiral structure adapted to the compensation area. At this time, it is necessary to increase the length of the heat exchange tube 10 of the replaced condenser, and then determine whether the increase is sufficient for configuration. At this time, the heat exchange tube 10 can be increased by staggered arrangement.

[0050] Specifically, as can be seen from the above, the length of the heat exchange tube 10 that can be accommodated by the second staggered arrangement method is greater than the length of the heat exchange tube 10 that can be accommodated by the first staggered arrangement method, and the length of the heat exchange tube 10 arranged in parallel is collected to form a second reference length set, which means to find out whether it is possible to satisfy the configuration of the first compensation area from these different "lengthened" lengths of the heat exchange tube 10.

[0051] If there is a second reference length in the second reference length set that is sufficient to configure the first compensation area, a third spiral pitch is obtained according to the first compensation area, and a fourth spiral pitch is obtained according to the second compensation area.

[0052] Specifically, in the same manner as described above to determine whether the first reference length and reference outer diameter are sufficient to configure the first compensation area, it is determined whether each combination of the second reference length and reference outer diameter is sufficient to configure the first compensation area. If a second reference length sufficient to configure the first compensation area exists in the second reference length set, then a second reference length sufficient to configure the first compensation area is found. Based on this appropriate length, a calculation idea similar to the previous one is used to calculate the third spiral pitch (for the inlet section 7) based on the first compensation area, and a fourth spiral pitch (for the outlet section 9) is calculated based on the second compensation area, thereby determining the new structural parameters of the heat exchange tube 10 to achieve a design that meets the heat exchange requirements.

[0053] Specifically, if the heat exchange tubes 10 need to be arranged in a staggered manner, the tube holes 4 of the inlet tube sheet 3 and the outlet tube sheet 6 need to be adaptively modified to ensure the stability and flue gas sealing of the heat exchange tubes 10 after the staggered arrangement.

[0054] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and its core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. An axial variable space flue gas condenser, characterized in that: include: A shell (1), wherein the shell (1) has a first space therein, and the shell (1) has a smoke inlet end and a smoke outlet end at two ends along its extension direction respectively; A flow guide tube (2), wherein the flow guide tube (2) has a flow guide space therein, the flow guide tube (2) is arranged in the first space, and both ends along the axial direction of the flow guide tube (2) are mounted on the inner wall of the shell (1); a heat exchange tube bundle (5), the heat exchange tube bundle (5) being arranged in the flow guide space, the heat exchange tube bundle (5) comprising a plurality of heat exchange tubes (10), condensate flowing in the heat exchange tubes (10), high-temperature flue gas entering from the flue gas inlet end flowing between the heat exchange tubes (10) and the flow guide tube (2), and the high-temperature flue gas after condensation being discharged from the flue gas outlet end; The heat exchange tube (10) is in a twisted spiral structure along its axial direction to form a heat exchange tube bundle (5) with a three-dimensional variable space, wherein the spiral pitch of the heat exchange tube (10) close to the flue gas inlet end is smaller than the spiral pitch of the heat exchange tube (10) close to the flue gas outlet end.

2. The axial variable space flue gas condenser according to claim 1, characterized in that: The portion of the heat exchange tube (10) close to the flue gas inlet end is the inlet section (7), the portion of the heat exchange tube (10) close to the flue gas outlet end is the outlet section (9), and the portion of the heat exchange tube (10) located between the inlet section (7) and the outlet section (9) is the middle section (8); the helical pitches of the inlet section (7) and the outlet section (9) remain unchanged, and the helical pitch of the twisted helical structure in the middle section (8) gradually increases in a direction from the inlet section (7) to the outlet section (9).

3. The axial variable space flue gas condenser according to claim 2, characterized in that: The rate of change of the spiral pitch of the intermediate section (8) is smaller than the relative change ratio of the spiral pitch between the inlet section (7) and the outlet section (9).

4. The axial variable space flue gas condenser according to claim 3, characterized in that: The high-temperature flue gas and the condensate flow in opposite directions.

5. The axial variable space flue gas condenser according to claim 4, characterized in that: The guide tube (2) is provided with an inlet tube sheet (3) and an outlet tube sheet (6) at both ends along the axial direction thereof, and the inlet tube sheet (3) and the outlet tube sheet (6) are respectively provided with a plurality of tube holes (4) adapted to the heat exchange tube (10), the inlet section (7) of the heat exchange tube (10) penetrates the tube hole (4) of the inlet tube sheet (3), and the outlet section (9) of the heat exchange tube (10) penetrates the tube hole (4) of the outlet tube sheet (6).

6. The axial variable space flue gas condenser according to claim 5, characterized in that: All the heat exchange tubes (10) are arranged in parallel or staggered. When staggered, any two adjacent heat exchange tubes (10) have the same staggered arrangement angle, which is the angle between an extension line of the heat exchange tube (10) and an extension line of the axis of the inlet tube sheet (3).

7. A method for preparing an axially variable space flue gas condenser, used for preparing a heat exchange tube bundle (5) in the axially variable space flue gas condenser according to claim 6, characterized in that: The following steps are involved: If the initial condenser does not meet the heat exchange requirement of the target unit high-temperature flue gas, a heat exchange compensation is obtained, where the heat exchange compensation is the difference between the target heat exchange specified by the target unit and the actual heat exchange of the initial condenser; The initial condenser has an initial heat exchange tube; According to the heat exchange compensation, a compensation area of ​​each heat exchange tube (10) in the heat exchange tube bundle (5) of the updated condenser is obtained, wherein the compensation area represents an effective heat exchange area that needs to be increased on each of the initial heat exchange tubes in order to achieve the heat exchange compensation; Respectively obtaining first segmented heat exchange requirements of the outlet section (9) and the inlet section (7) of the updated heat exchange tube (10), and allocating the compensation area according to the first segmented heat exchange requirements of the outlet section (9) and the inlet section (7) to obtain a first spiral pitch of the inlet section (7) and a second spiral pitch of the outlet section (9); Each of the heat exchange tubes (10) is manufactured with the first spiral pitch and the second spiral pitch, thereby obtaining the heat exchange tube bundle (5).

8. The method for preparing the axially variable space flue gas condenser according to claim 7, characterized in that: The method of allocating the compensation area according to the first segmented heat exchange requirements of the outlet section (9) and the inlet section (7) to obtain a first spiral pitch of the inlet section (7) and a second spiral pitch of the outlet section (9) specifically comprises the following steps: Allocating the compensation area according to the ratio of the first segmented heat exchange requirements of the inlet section (7) and the outlet section (9) to obtain a first compensation area of ​​the inlet section (7) and a second compensation area of ​​the outlet section (9); The first spiral pitch is obtained according to the first compensation area, and the second spiral pitch is obtained according to the second compensation area.

9. The method for preparing the axially variable space flue gas condenser according to claim 8, characterized in that: After allocating the compensation area according to the ratio of the first segmented heat exchange requirements of the inlet section (7) and the outlet section (9) to obtain the first compensation area of ​​the inlet section (7) and the second compensation area of ​​the outlet section (9), the method further comprises the following steps: According to the structural dimensions of the initial condenser, a first reference length and a reference outer diameter are obtained; wherein the first reference length is the length of a center line connecting the tube hole (4) of the inlet tube sheet (3) and the corresponding tube hole (4) on the outlet tube sheet (6), and the reference outer diameter is the outer diameter of the heat exchange tube (10) of the initial condenser; determining whether the first reference length and the reference outer diameter are sufficient to configure the first compensation area; The method of obtaining the first spiral pitch according to the first compensation area and obtaining the second spiral pitch according to the second compensation area specifically comprises the following steps: If so, the first spiral pitch is obtained according to the first compensation area, and the second spiral pitch is obtained according to the second compensation area.

10. The method for preparing the axially variable space flue gas condenser according to claim 9, characterized in that: After determining whether the first reference length and the reference outer diameter are sufficient to configure the first compensation area, the following steps are also included: If not, obtaining a second reference length set, the second reference length set comprising a plurality of second reference lengths, the second reference length being the length of a center line connecting the tube hole (4) of the inlet tube sheet (3) and the tube hole (4) on the outlet tube sheet (6) that is offset therefrom, the second reference length being greater than the first reference length; If there is a second reference length in the second reference length set that is sufficient to configure the first compensation area, a third spiral pitch is obtained according to the first compensation area, and a fourth spiral pitch is obtained according to the second compensation area.

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