An in-tube evaporation wound-tube steam generator and its usage method

Abstract

This invention relates to the field of steam generators. To address the problems of large footprint, high manufacturing cost, and difficulty in effectively separating gas and liquid when the density difference between the gas and liquid is small, this invention provides an in-tube evaporation wound-tube steam generator, comprising: a shell, a liquid pipe, a vapor-liquid separator, a return pipe, and a liquid level measuring cylinder. The shell has a heating medium outlet and a heating medium inlet. The liquid pipe is located inside the shell, and a heating medium flow channel is formed between the outer wall of the liquid pipe and the inner wall of the shell. The vapor-liquid separator is connected to the heating medium flow channel. The upper end of the return pipe is connected to the liquid outlet of the vapor-liquid separator. The lower end of the return pipe is connected to the liquid level measuring cylinder. This invention can effectively achieve direct-flow evaporation of the liquid and facilitate convenient operation control. When the heating medium provides insufficient heat, the heat status of the heating medium can be determined by monitoring changes in the liquid level.

Description

Technical Field

[0001] This invention relates to the field of steam generators, and more specifically, to an in-tube evaporation wound-tube steam generator and its method of use. Background Technology

[0002] Spiral wound tube heat exchangers are a new type of high-efficiency heat exchanger developed in the last two decades. They are widely used in heating or cooling processes in industries such as coal chemical, petrochemical, large-scale fertilizer, natural gas processing, and comprehensive energy utilization. The main advantages of this type of heat exchanger are: 1) compact structure; 2) high heat transfer efficiency, enabling heat transfer with large temperature rise and small temperature difference; 3) low temperature stress between the heat exchange tubes and the tube sheet; and 4) ability to achieve simultaneous heat exchange by multiple streams (≥2 streams). Using spiral wound tube heat exchangers for liquid direct-flow evaporation can reduce equipment size and weight, facilitate site layout, and save equipment costs.

[0003] Existing liquid evaporation structures are mainly based on non-DC evaporation and DC evaporation.

[0004] For non-direct-flow evaporation, the evaporation structure is a circulating evaporation structure, such as the common shell-and-tube waste heat boiler. This system consists of a heat exchanger, a steam drum (vapor-liquid separator), risers, and downcomers, forming the steam generation system. The heat exchanger heats the liquid for incomplete evaporation, producing a two-phase vapor-liquid fluid that enters the steam drum through the risers for vapor-liquid separation. The separated saturated liquid, along with makeup liquid, enters the heat exchanger through the downcomers for circulating heating and evaporation. During the heat exchange process, the convective heat exchange between the medium to be evaporated and the heating medium improves the heat exchange efficiency. Its disadvantages are: it is difficult to achieve liquid evaporation with a single device; it requires a large footprint and has high investment costs; and when the density difference between the gas and liquid is small, such as in the evaporation of high-pressure liquid carbon dioxide, gas-liquid separation is difficult to achieve.

[0005] For direct-flow evaporation structures, such as the common autoclave evaporator, liquid evaporation is carried out in a large-volume pool. Although a single device can complete the process, external evaporation requires a large liquid surface space and volume, which in turn requires a large shell volume. When the operating pressure of the evaporating liquid is high, the pressure-bearing shell wall is thicker, resulting in a large size, heavy weight, large space occupation, and high equipment cost. When the density difference between gas and liquid is small, it is also difficult to achieve gas-liquid separation. Summary of the Invention

[0006] The purpose of this invention is to provide an in-tube evaporation wound tube steam generator and its usage method, which solves the problems of large footprint and high manufacturing cost of existing steam generators, as well as the difficulty in effectively achieving gas-liquid separation when the density difference between gas and liquid is small.

[0007] The embodiments of the present invention are achieved through the following technical solutions:

[0008] An in-tube evaporation wound-tube steam generator includes: a shell, a liquid pipe, a vapor-liquid separator, a reflux pipe, and a liquid level measuring cylinder. The shell is provided with a heating medium outlet and a heating medium inlet. The liquid pipe is disposed inside the shell, and a heating medium flow channel is formed between the outer wall of the liquid pipe and the inner wall of the shell. The vapor-liquid separator is connected to the heating medium flow channel. The upper end of the reflux pipe is connected to the liquid outlet of the vapor-liquid separator. The lower end of the reflux pipe is connected to the liquid level measuring cylinder.

[0009] Preferably, the outer casing includes: an upper tube box, a main shell, and an upper tube sheet. The vapor-liquid separator is located inside the upper tube box, and the upper tube box is provided with a steam outlet. The bottom end of the upper tube box is connected to the top end of the main shell, and the main shell is provided with a heating medium outlet and a heating medium inlet. The upper tube sheet is connected to the bottom end of the upper tube box and / or the top end of the main shell. The upper tube sheet is provided with an upper connecting hole, which communicates with the top end of the return pipe. The upper tube sheet is also provided with an upper through hole, through which the upper tube box communicates with the liquid pipe.

[0010] Preferably, the upper end of the liquid level measuring cylinder is connected to the upper pipe box via a steam connection pipe.

[0011] Preferably, the outer casing further includes: a lower tube box and a lower tube sheet, wherein the lower tube box is provided with a liquid inlet; the lower tube sheet is connected to the top end of the lower tube box and / or the bottom end of the main casing; the lower tube sheet is provided with a lower connecting hole, which communicates with the bottom end of the return pipe; the lower tube sheet is provided with a lower through hole, through which the lower tube box communicates with the liquid pipe.

[0012] Preferably, the measuring cylinder is provided with a reflux port, which is connected to the lower tube box.

[0013] Preferably, the lower connecting hole is connected to the liquid level measuring cylinder through an extension tube.

[0014] Preferably, the liquid tube is spirally wound around the periphery of the return tube.

[0015] A method of using the aforementioned in-tube evaporation wound tube steam generator includes:

[0016] The heating medium enters the heating medium flow channel from the heating medium inlet of the outer shell, flows downward to the heating medium outlet, and then flows out.

[0017] The medium to be evaporated flows from the bottom of the liquid tube to the top of the liquid tube;

[0018] After the medium to be evaporated exchanges heat with the heating medium, the processed medium is obtained and then enters the vapor-liquid separator.

[0019] When the processed medium is a gas-liquid mixture, the two phases are separated by a gas-liquid separator. The gas phase is output from the steam outlet of the outer shell, and the liquid phase enters the liquid level measuring cylinder from the return pipe.

[0020] Preferably, the method of use further includes:

[0021] The relationship between the liquid level change rate, heating medium parameters, and evaporation medium parameters in the liquid level measuring cylinder is obtained by using historical data.

[0022] Adjust the parameters of the heating medium and / or the medium to be evaporated based on the measured rate of liquid level change.

[0023] Preferably, when the parameters of the medium to be evaporated are fixed, the minimum heating medium parameter corresponding to the liquid level change rate being 0 is obtained;

[0024] When the minimum heating medium parameter is used in the evaporation operation, if the liquid level change rate is greater than 0, the equipment cleaning or maintenance should be determined based on the relationship between the liquid level change rate and the set threshold.

[0025] The present invention has at least the following beneficial effects:

[0026] This invention's structure effectively achieves direct-flow evaporation of liquids and facilitates convenient operation control. When the heating medium provides insufficient heat, and the evaporating gas carries liquid, vapor-liquid separation can be achieved. The separated liquid is collected through a return pipe connecting the upper and lower tube sheets and led out to an external liquid level measuring cylinder. When the heating medium provides excessive heat, the liquid completely evaporates, and the liquid level in the measuring cylinder remains unchanged. When the heating medium provides insufficient heat, the liquid partially evaporates, and the liquid level in the measuring cylinder rises. By monitoring the changes in the liquid level in the measuring cylinder, the heat supply of the heating medium can be intuitively judged, providing operational guidance for system control. Because this invention's structure effectively achieves direct-flow evaporation of liquids, a large-volume liquid tank is not required, reducing the equipment size. Furthermore, the direct-flow evaporation method, combined with the control of the heating medium, ensures complete evaporation of the liquid, reducing the load on the vapor-liquid separator. When the steam generator provided by this invention is used for liquid carbon dioxide evaporation in a carbon dioxide energy storage system, since the liquid carbon dioxide flows through the liquid pipe, its pressure does not directly act on the outer shell, thus reducing the shell thickness and lowering the equipment's manufacturing cost, transportation cost, and floor space. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of an in-tube evaporation wound tube steam generator;

[0029] Figure 2 A schematic diagram of the first structure of the main shell;

[0030] Figure 3 A schematic diagram of the second structure of the main shell;

[0031] Figure 4 This is a schematic diagram of the upper pipe box structure;

[0032] Figure 5 This is a schematic diagram of the lower pipe box structure;

[0033] Figure 6 This is a schematic diagram of the liquid level measuring cylinder;

[0034] Icons: 1-Outer shell, 101-Heating medium outlet, 102-Heating medium inlet, 103-Upper tube box, 1031-Steam outlet, 104-Main shell, 105-Upper tube sheet, 1051-Upper connecting hole, 1052-Upper through hole, 106-Lower tube box, 1061-Liquid inlet, 107-Lower tube sheet, 1071-Lower connecting hole, 1072-Lower through hole, 2-Liquid pipe, 3-Heating medium flow channel, 4-Vacuum-liquid separator, 5-Return pipe, 6-Level measuring cylinder, 601-Return port, 7-Vacuum-connecting pipe, 8-Extension pipe, 9-Level gauge. Detailed Implementation

[0035] To make the objectives, methods, and advantages of the embodiments of the present invention clearer, the methods in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0036] Example 1: As Figure 1-3 As shown, an in-tube evaporation wound tube type steam generator includes: a shell 1, a liquid pipe 2, a vapor-liquid separator 4, a return pipe 5, and a liquid level measuring cylinder 6. The shell 1 is provided with a heating medium outlet 101 and a heating medium inlet 102. The liquid pipe 2 is disposed inside the shell 1, and a heating medium flow channel 3 is formed between the outer wall of the liquid pipe 2 and the inner wall of the shell 1. The vapor-liquid separator 4 is connected to the heating medium flow channel 3. The upper end of the return pipe 5 is connected to the liquid outlet of the vapor-liquid separator 4. The lower end of the return pipe 5 is connected to the liquid level measuring cylinder 6.

[0037] In practical implementation, the typical application scenario of the steam generator provided in this embodiment is the evaporation of liquid carbon dioxide in a novel carbon dioxide energy storage system. For example, carbon dioxide power generation and storage technology, officially known as supercritical carbon dioxide (S-CO2) energy storage and power generation technology. This technology cleverly utilizes the highly efficient energy conversion performance of carbon dioxide in a supercritical state (temperature above 31.1℃, pressure above 7.38MPa, possessing both gas and liquid characteristics) to achieve bidirectional storage and release of electrical energy and thermal / pressure energy, making it a highly innovative new energy storage technology. Its core lies in organically combining the compression and expansion processes of carbon dioxide with thermodynamic cycles through a closed-loop system to achieve efficient energy storage and power generation, and is considered one of the revolutionary technologies in the next generation of high-efficiency energy storage and power generation.

[0038] Energy storage stage: Carbon dioxide (or recovered industrial CO2) at ambient temperature and pressure is pressurized to a supercritical state (e.g., pressure reaches 20-30 MPa, temperature approximately 100-300℃) by a compressor. During this process, the heat generated by compression is collected by a heat exchanger and stored in a high-temperature thermal storage device (such as molten salt or solid thermal storage materials). The compressed supercritical CO2 enters a cryogenic storage tank (temperature approximately 50-100℃, under high pressure), while the heat of compression is stored in a high-temperature thermal storage system, thus achieving dual storage of "thermal energy + pressure energy".

[0039] Energy release stage: Low-temperature, high-pressure CO2 flows out of the storage tank and first absorbs high-temperature heat (temperature can be raised to 500-700℃) from the heat exchanger, transforming into high-temperature supercritical CO2. The high-temperature, high-pressure CO2 drives the turbine generator to expand and do work, driving the impeller to generate electricity. Afterwards, the CO2 is cooled and depressurized to return to its initial state, entering the next cycle.

[0040] As can be seen from the above, CO2 is always under high pressure during the energy release phase. If a circulating evaporation structure is used, the pressure resistance requirements of various parts of the equipment are high. Therefore, using direct current evaporation can not only reduce the size of the equipment, but also reduce the pressure resistance requirements of certain parts of the equipment.

[0041] To ensure effective direct current evaporation, this embodiment includes a return pipe 5 and a liquid level measuring cylinder 6. When the heating medium provides insufficient heat, and the gas produced during evaporation carries liquid, vapor-liquid separation can be achieved. The separated liquid is collected through the return pipe 5, which connects the upper and lower tube sheets 107, and led out to the external liquid level measuring cylinder 6. When the heating medium provides excessive heat, the liquid completely evaporates, and the liquid level in the liquid level measuring cylinder 6 does not rise. When the heating medium provides insufficient heat, the liquid will partially evaporate, and the liquid level in the liquid level measuring cylinder 6 will rise. Thus, by monitoring the changes in the liquid level in the liquid level measuring cylinder 6, the heat supply of the heating medium can be intuitively judged, providing operational guidance for system control.

[0042] like Figure 1 As shown, a level gauge 9 can be installed in the level measuring cylinder 6. The heating medium is delivered by a variable frequency pump, and the delivery parameters of the heating medium are regulated by an existing DCS control system. Exemplarily, after the level gauge 9 transmits the detected level data to the DCS control system, the analysis module analyzes and judges the data, and then controls the speed of the variable frequency pump. Exemplarily, DC evaporation can also be regulated by adjusting the temperature of the heating medium.

[0043] During the heat exchange process, the heating medium enters the heating medium flow channel 3 between the outer shell 1 and the liquid pipe 2 from the heating medium inlet 102, then flows downwards and exits from the heating medium outlet 101. The medium to be evaporated, such as liquid CO2, enters the liquid pipe 2 from below, flows upwards and absorbs heat. After undergoing preheating, saturation, and a gradual superheating process where the cross-sectional vapor content rises from 0 to 100%, the liquid enters the vapor-liquid separator 4. When incomplete evaporation occurs, the liquid separated by the vapor-liquid separator 4 falls back to the return pipe 5, and then enters the liquid measuring cylinder. The liquid level can be visually reflected by the level gauge 9 installed on the liquid level measuring port of the liquid level measuring cylinder.

[0044] Since the steam generator provided in this embodiment can effectively achieve direct-flow evaporation of liquid, a large-volume liquid tank is not required, and the equipment volume can be reduced. In addition, the direct-flow evaporation method combined with the regulation of the heating medium can ensure complete evaporation of liquid, reducing the load on the vapor-liquid separator 4. When the steam generator provided in this embodiment is used for liquid carbon dioxide evaporation in a carbon dioxide energy storage system, since the liquid carbon dioxide flows through the liquid pipe 2, its pressure will not directly act on the outer shell 1, thereby reducing the thickness of the outer shell 1 and reducing the manufacturing cost and area of ​​the equipment.

[0045] The heating medium can be high-temperature molten salt, or high-temperature gaseous medium, such as high-temperature air, flue gas, chemical waste heat gas and other media.

[0046] In this embodiment, each interface or pipe opening can be connected by flange, welding, or other suitable connection methods. Components can be equipped with safety accessories such as temperature measurement, pressure measurement, and safety relief devices, as well as welding accessories such as supports and lifting lugs, as needed.

[0047] Example 2: As Figure 1-4As shown, in this embodiment, the outer casing 1 includes: an upper tube box 103, a main casing 104, and an upper tube sheet 105. The vapor-liquid separator 4 is located inside the upper tube box 103. The upper tube box 103 is provided with a steam outlet 1031. The bottom end of the upper tube box 103 is connected to the top end of the main casing 104. The main casing 104 is provided with a heating medium outlet 101 and a heating medium inlet 102. The upper tube sheet 105 is connected to the bottom end of the upper tube box 103 and / or the top end of the main casing 104. The upper tube sheet 105 is provided with an upper connecting hole 1051, which communicates with the top end of the return pipe 5. The upper tube sheet 105 is provided with an upper through hole 1052, through which the upper tube box 103 communicates with the liquid pipe 2.

[0048] In specific implementation, the upper tube box 103 can be a pressure-bearing shell, and a steam output pipe can be installed at the upper end of the upper tube box 103. When the liquid is separated by the vapor-liquid separator 4, the liquid can be collected at the upper through hole 1052 of the upper tube plate 105, and then flow through the liquid pipe 2 into the liquid level measuring cylinder 6. The upper through hole 1052 can be located at the center of the upper tube plate 105, and thus the return pipe 5 is located at the center of the outer shell 1.

[0049] Example 3: As Figure 1 As shown, in this embodiment, the upper end of the liquid level measuring cylinder 6 is connected to the upper pipe box 103 through the steam connection pipe 7.

[0050] In the specific implementation process, after connecting the inner cavity of the upper tube box 103 and the inner cavity of the liquid level measuring cylinder 6, the pressure inside the liquid level measuring cylinder 6 and the central tube can be balanced to ensure that the liquid level height inside the liquid level measuring cylinder 6 is consistent with the liquid level height inside the central tube.

[0051] Example 4: Figure 1 and Figure 5 As shown, in this embodiment, the outer casing 1 further includes: a lower tube box 106 and a lower tube plate 107. The lower tube box 106 is provided with a liquid inlet 1061. The lower tube plate 107 is connected to the top end of the lower tube box 106 and / or the bottom end of the main casing 104. The lower tube plate 107 is provided with a lower connecting hole 1071, which communicates with the bottom end of the return pipe 5. The lower tube plate 107 is provided with a lower through hole 1072, through which the lower tube box 106 communicates with the liquid pipe 2.

[0052] In specific implementation, the lower tube box 106 can be a pressure-bearing shell, and the return pipe 5 is located between the upper tube sheet 105 and the lower tube sheet 107. The arrangement of the upper tube sheet 105 and the lower tube sheet 107 not only facilitates the installation of the return pipe 5, but also allows for the installation of the liquid pipe 2. In addition, the upper connecting hole 1051, the lower connecting hole 1071, the upper through hole 1052, and the lower through hole 1072 are used to separate the paths of the medium to be evaporated and the return liquid.

[0053] After the evaporation medium enters from the lower tube box 106, it sequentially passes through the lower connecting hole 1071, the liquid pipe 2, the upper connecting hole 1051, the upper tube box 103, and the vapor-liquid separator 4 for vapor-liquid separation.

[0054] Example 5: Figure 6 As shown, in this embodiment, the measuring cylinder is provided with a return port 601, which is connected to the lower tube box 106.

[0055] In the specific implementation process, a valve can be installed at the return port 601 of the liquid level measuring cylinder 6, through which the incompletely evaporated liquid can be returned to the lower tube box 106 for secondary evaporation.

[0056] Example 6: As Figure 1 As shown, in this embodiment, the lower connecting hole 1071 is connected to the liquid level measuring cylinder 6 through the extension tube 8.

[0057] In the specific implementation process, the extension pipe 8 leads the liquid in the return pipe 5 to the liquid level measuring cylinder 6 on the side of the outer casing 1.

[0058] Example 7: As Figure 1-2 As shown, in this embodiment, the liquid tube 2 is spirally wound around the periphery of the return tube 5.

[0059] In the specific implementation process, the specific structure of the liquid tube 2 is not shown in the figure. To increase the heat transfer effect between the medium to be evaporated and the heating medium, in this embodiment, the liquid tube 2 can be spirally wound around the outside of the return pipe 5 in a spring-like shape. There can be a gap between the liquid tube 2 and the return pipe 5 to increase the heat transfer area between the heating medium and the liquid tube 2. By using the spirally wound liquid tube 2, efficient heat transfer is achieved, which not only enables direct-flow evaporation of liquid but also saves more than 50% of space and more than 40% of equipment costs.

[0060] Example 8: This example provides a method for using the aforementioned in-tube evaporation wound tube steam generator, including:

[0061] The heating medium enters the heating medium flow channel 3 from the heating medium inlet 102 of the outer shell 1, flows downward to the heating medium outlet 101 and then flows out;

[0062] The medium to be evaporated flows from the bottom end of liquid tube 2 to the top end of liquid tube 2;

[0063] After the medium to be evaporated exchanges heat with the heating medium, the processed medium is obtained and then enters the vapor-liquid separator 4.

[0064] When the processed medium is a gas-liquid mixture, the two phases are separated by the gas-liquid separator 4. The gas phase is output from the steam outlet 1031 of the outer shell 1, and the liquid phase enters the liquid level measuring cylinder 6 from the return pipe 5.

[0065] In practice, liquid phase is separated only when the liquid is not completely evaporated, and then enters the liquid level measuring cylinder 6 through the return pipe 5. When the liquid is completely evaporated, all the steam is output.

[0066] Example 9: In this example, the method of use further includes:

[0067] The relationship between the liquid level change rate, heating medium parameters, and evaporation medium parameters in the liquid level measuring cylinder 6 is obtained by using historical data.

[0068] Adjust the parameters of the heating medium and / or the medium to be evaporated based on the measured rate of liquid level change.

[0069] In practice, historical data can be derived from experimental data and historical operational data. Heating medium parameters can be the flow rate or temperature of the heating medium. Parameters of the medium to be evaporated can include pressure, temperature, and flow rate, etc.

[0070] When the steam generator provided by this invention is used for the evaporation of liquid carbon dioxide in a carbon dioxide energy storage system, the parameters of the liquid carbon dioxide are relatively stable, which also ensures the stability of the release rate during the energy release process. Therefore, this embodiment can explore the relationship between the liquid level change rate and the parameters of the medium to be evaporated. Since changing the temperature of the medium to be evaporated has a time delay, the parameters of the medium to be evaporated in this embodiment can be selected as flow rate. By regulating the flow rate, the heat transfer can be regulated, thereby regulating the evaporation effect of the liquid.

[0071] When the steam generator provided by this invention is used for the evaporation of conventional liquids, the flow rate or temperature of the medium to be evaporated can also be adjusted to control the evaporation effect of the liquid.

[0072] Example 10: In this example, when the parameters of the medium to be evaporated are constant, the minimum heating medium parameter corresponding to the liquid level change rate being 0 is obtained;

[0073] When the minimum heating medium parameter is used in the evaporation operation, if the liquid level change rate is greater than 0, the equipment cleaning or maintenance should be determined based on the relationship between the liquid level change rate and the set threshold.

[0074] In practice, after obtaining the relationship curves between the liquid level change rate, heating medium parameters, and the parameters of the medium to be evaporated from historical data, the minimum heating medium parameters corresponding to a liquid level change rate of 0 on the curve are adopted in actual production. For example, the minimum heating medium flow rate required for the heating medium to completely evaporate the liquid. If incomplete evaporation occurs under the aforementioned heating medium parameters while the parameters of the medium to be evaporated remain unchanged, i.e., the liquid level changes, it indicates that the heat transfer efficiency of the equipment has decreased during long-term use, such as partial blockage or scaling in the pipes.

[0075] The threshold value can be set according to actual needs. It is not economical or practical to shut down the equipment for cleaning or maintenance when the liquid level change rate is slow. Therefore, a threshold can be set. Before the liquid level change rate reaches the threshold, secondary evaporation is performed via reflux. When the liquid level change rate reaches the threshold, the equipment is cleaned or maintained to restore its heat transfer efficiency. Whether the heat transfer efficiency has been restored can also be determined by observing the liquid level change.

[0076] This embodiment can ensure the direct evaporation effect of the liquid and the vapor-liquid separation effect when the saturation pressure of the medium to be evaporated is high and the pressure of the heating medium is low by adjusting the heating medium parameters. Evaporation inside the pipe helps to reduce the thickness of the shell-side pressure-bearing shell, which is more conducive to reducing the weight of the equipment and reducing the material cost, manufacturing cost and transportation cost of the equipment.

[0077] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A tube-type steam generator with in-tube evaporation and winding, characterized in that, include: The outer casing (1) is provided with a heating medium outlet (101) and a heating medium inlet (102); A liquid pipe (2) is disposed inside the outer shell (1), and a heating medium flow channel (3) is formed between the outer wall of the liquid pipe (2) and the inner wall of the outer shell (1); A vapor-liquid separator (4) is connected to the heating medium flow channel (3); Return pipe (5), the upper end of which is connected to the liquid outlet of the vapor-liquid separator (4); The liquid level measuring cylinder (6) is connected to the lower end of the return pipe (5); The operating method of an in-tube evaporation wound steam generator includes: The heating medium enters the heating medium flow channel from the heating medium inlet of the outer shell, flows downward to the heating medium outlet, and then flows out. The medium to be evaporated flows from the bottom of the liquid tube to the top of the liquid tube; After the medium to be evaporated exchanges heat with the heating medium, the processed medium is obtained and then enters the vapor-liquid separator. When the processed medium is a gas-liquid mixture, the two phases are separated by a gas-liquid separator. The gas phase is output from the steam outlet of the shell, and the liquid phase enters the liquid level measuring cylinder from the return pipe. The usage method also includes: The relationship between the liquid level change rate, heating medium parameters, and evaporation medium parameters in the liquid level measuring cylinder is obtained by using historical data. Adjust the parameters of the heating medium and / or the parameters of the medium to be evaporated based on the measured rate of liquid level change. When the parameters of the medium to be evaporated are constant, obtain the minimum heating medium parameter corresponding to the liquid level change rate of 0. When the minimum heating medium parameter is used in the evaporation operation, if the liquid level change rate is greater than 0, the equipment cleaning or maintenance should be determined based on the relationship between the liquid level change rate and the set threshold. The medium to be evaporated is liquid carbon dioxide.

2. The in-tube evaporation wound tube steam generator according to claim 1, characterized in that, The outer casing (1) includes: Upper tube box (103), the vapor-liquid separator (4) is located inside the upper tube box (103), and the upper tube box (103) is provided with a steam outlet (1031); The main housing (104) has the bottom end of the upper pipe box (103) connected to the top end of the main housing (104), and the main housing (104) is provided with the heating medium outlet (101) and the heating medium inlet (102); The upper tube sheet (105) is connected to the bottom end of the upper tube box (103) and / or the top end of the main shell (104); the upper tube sheet (105) is provided with an upper connecting hole (1051), which is connected to the top end of the return pipe (5); the upper tube sheet (105) is provided with an upper through hole (1052), and the upper tube box (103) is connected to the liquid pipe (2) through the upper through hole (1052).

3. The in-tube evaporation wound tube steam generator according to claim 2, characterized in that, The upper end of the liquid level measuring cylinder (6) is connected to the upper pipe box (103) through the steam connection pipe (7).

4. The in-tube evaporation wound tube steam generator according to claim 1, characterized in that, The outer casing (1) also includes: The lower pipe box (106) is provided with a liquid inlet (1061); The lower tube sheet (107) is connected to the top end of the lower tube box (106) and / or the bottom end of the main housing (104); the lower tube sheet (107) is provided with a lower connecting hole (1071), which is connected to the bottom end of the return pipe (5); the lower tube sheet (107) is provided with a lower through hole (1072), through which the lower tube box (106) is connected to the liquid pipe (2).

5. The in-tube evaporation wound tube steam generator according to claim 4, characterized in that, The measuring cylinder is provided with a return port (601), which is connected to the lower tube box (106).

6. The in-tube evaporation wound tube steam generator according to claim 4, characterized in that, The lower connecting hole (1071) is connected to the liquid level measuring cylinder (6) through the extension tube (8).

7. The in-tube evaporation wound tube steam generator according to any one of claims 1-6, characterized in that, The liquid tube (2) is spirally wound around the periphery of the return tube (5).

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