High-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl replenishment

Abstract

This invention discloses a high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical cyclone liquid replenishment, relating to the field of condenser technology. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical cyclone liquid replenishment includes a shell, a liquid distributor, a mechanical cyclone liquid replenishment device, and a gas-liquid separation device. A heat exchange channel is formed inside the shell, and the shell has a steam inlet and a condensate outlet communicating with the heat exchange channel. A water inlet is located at the top of the shell. The liquid distributor is located inside the shell and near the water inlet, and the liquid distributor has multiple distributing holes. The mechanical cyclone liquid replenishment device includes a liquid collecting pump, a cyclone nozzle, and a connecting pipe. The liquid collecting pump and the cyclone nozzle are located on the inner bottom wall of the shell, and the connecting pipe connects the liquid collecting pump and the cyclone nozzle. The gas-liquid separation device is located at the top of the shell. The technical solution provided by this invention can improve heat exchange efficiency and simultaneously recycle the bottom accumulated liquid to suppress dry spot phenomenon.

Description

Technical Field

[0001] This invention relates to the field of condenser technology, and in particular to a high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl replenishment. Background Technology

[0002] Steam, due to its high latent heat and easy regulation, is widely regarded as an ideal heat carrier. Current technologies typically utilize high-temperature heat pumps to supply steam. In high-temperature heat pump systems, the condenser is a key heat exchange component, its function being to allow external cooling fluid to absorb heat from the refrigerant vapor, thereby condensing the refrigerant into a liquid. Shell-and-tube condensers are widely used due to their simple structure, stable operation, and wide applicability in high-temperature and high-pressure applications. If falling film evaporation is used in a shell-and-tube condenser, the liquid can be distributed into a thin film flowing along the outer wall of the tubes, absorbing heat from inside the tubes to complete a phase change, achieving efficient heat exchange and low power consumption; however, shell-and-tube condensers are prone to dry spots and liquid accumulation at the bottom during use. Summary of the Invention

[0003] The main objective of this invention is to propose a high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl replenishment, which aims to improve heat exchange efficiency while recycling the bottom liquid to suppress dry spot phenomenon.

[0004] To achieve the above objectives, the present invention proposes a high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical cyclone replenishment, comprising:

[0005] The shell has a heat exchange channel formed inside it, and the shell is provided with a steam inlet and a condensate outlet communicating with the heat exchange channel. The top of the shell is provided with a water inlet.

[0006] A liquid distributor is disposed inside the housing and near the water inlet, and the liquid distributor has multiple liquid distribution holes.

[0007] A mechanical cyclone replenishment device, comprising a liquid collecting pump, a cyclone nozzle, and a connecting pipe, wherein the liquid collecting pump and the cyclone nozzle are disposed on the inner bottom wall of the housing, and the connecting pipe connects the liquid collecting pump and the cyclone nozzle;

[0008] A gas-liquid separation device is located at the top of the housing.

[0009] In one embodiment, the mechanical swirling liquid replenishment device includes a plurality of swirling nozzles, which are spaced apart along the length of the housing, and the connecting pipe connects the liquid collecting pump and the plurality of swirling nozzles.

[0010] In one embodiment, the swirling nozzle comprises a valve core and an atomizing chamber that are connected in communication.

[0011] In one embodiment, the housing is characterized by having a liquid level sensor.

[0012] In one embodiment, the top of the housing is provided with a plurality of water inlets, which are spaced apart along the length of the housing.

[0013] In one embodiment, the shell includes a shell body, a front tube sheet, a rear tube sheet, a front end cap, a rear end cap, and a plurality of heat exchange tubes. The water inlet is provided at the top of the shell body. The front tube sheet and the rear tube sheet are located at both ends of the shell body. The plurality of heat exchange tubes are located between the front tube sheet and the rear tube sheet. The front tube sheet, the rear tube sheet, and the plurality of heat exchange tubes form the heat exchange channel. The front end cap is located on the front tube sheet and forms the steam inlet and the condensate outlet. The rear end cap is located on the rear tube sheet.

[0014] In one embodiment, each heat exchange tube is provided with a plurality of temperature sensors spaced apart.

[0015] In one embodiment, an acoustic emission sensor is provided inside the housing.

[0016] In one embodiment, the bottom end of the housing is provided with a drain outlet, and a control valve is provided inside the drain outlet.

[0017] In one embodiment, the diameter of the liquid separating hole is d, where 0.5 mm ≤ d ≤ 2.0 mm.

[0018] In the technical solution of this invention, high-temperature refrigerant vapor can enter the heat exchange channel through the vapor inlet of the shell, condense and release heat in the heat exchange channel, and finally be discharged from the condensate outlet in the form of condensate water. Cooling water enters the shell through the water inlet, and then comes into uniform contact with the heat exchange channel through multiple liquid distribution holes on the liquid distributor, forming falling film evaporation, increasing the heat exchange area, improving heat exchange efficiency, and enabling heat to be transferred and absorbed more effectively. Furthermore, the gas-liquid separation device can separate the generated vapor into gas and liquid, making the discharged vapor purer and drier, meeting usage requirements, and improving steam quality. Simultaneously, the liquid collection pump and cyclone nozzle are located on the bottom wall of the shell, which can centrifuge and atomize the water deposited at the bottom of the shell and spray it upwards, allowing the bottom liquid to be recycled, improving the uniformity of the water film, and effectively suppressing dry spot phenomena. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 A schematic diagram of a high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical cyclone replenishment provided by the present invention;

[0021] Figure 2 for Figure 1 A sectional view;

[0022] Figure 3 This is a schematic diagram of one embodiment of the liquid distributor;

[0023] Figure 4 The flowchart of the swirling liquid replenishment process is shown in one embodiment of the high-temperature steam direct outlet shell-and-tube condenser with falling film evaporation and mechanical swirling liquid replenishment provided by the present invention.

[0024] Explanation of icon numbers:

[0025] 11. Shell body; 121. Front tube sheet; 122. Rear tube sheet; 131. Front end cap; 132. Rear end cap; 14. Steam inlet; 15. Condensate outlet; 16. Drain outlet; 17. Water inlet; 18. Heat exchange tube; 20. Liquid distributor; 21. Liquid distribution hole; 31. Liquid collecting pump; 32. Swirl nozzle; 40. Gas-liquid separation device.

[0026] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0029] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0030] This invention proposes a high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl replenishment.

[0031] Please see Figure 1 and Figure 2 In one embodiment of the present invention, the high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical cyclone replenishment includes a shell, a liquid distributor 20, a mechanical cyclone replenishment device, and a gas-liquid separation device 40; a heat exchange channel is formed inside the shell, and the shell is provided with a steam inlet 14 and a condensate outlet 15 communicating with the heat exchange channel, and a water inlet 17 is provided at the top of the shell; the liquid distributor 20 is located inside the shell and is located near the water inlet 17, and the liquid distributor 20 is provided with a plurality of liquid distribution holes 21; the mechanical cyclone replenishment device includes a liquid collecting pump 31, a cyclone nozzle 32, and a connecting pipe, the liquid collecting pump 31 and the cyclone nozzle 32 are located on the inner bottom wall of the shell, and the connecting pipe connects the liquid collecting pump 31 and the cyclone nozzle 32; the gas-liquid separation device 40 is located at the top of the shell.

[0032] In the technical solution of this invention, high-temperature refrigerant vapor can enter the heat exchange channel through the steam inlet 14 of the shell, condense and release heat in the heat exchange channel, and finally be discharged from the condensate outlet 15 in the form of condensate water. Cooling water enters the shell through the water inlet 17, and then comes into uniform contact with the heat exchange channel through multiple liquid distribution holes 21 on the liquid distributor 20 to form falling film evaporation, increase the heat exchange area, improve the heat exchange efficiency, and enable heat to be transferred and absorbed more effectively. In addition, the gas-liquid separation device 40 can separate the generated steam into gas and liquid, making the discharged steam purer and drier, meeting the usage requirements and improving the steam quality. At the same time, the liquid collection pump 31 and the swirl nozzle 32 are located on the bottom wall of the shell, which can centrifuge and atomize the water deposited at the bottom of the shell and spray it upward, so that the bottom liquid can be recycled, improve the uniformity of the water film, and effectively suppress the dry spot phenomenon.

[0033] Specifically, in one embodiment of the present invention, please refer to... Figure 1and Figure 2 The shell includes a shell body, a front tube sheet 121, a rear tube sheet 122, a front end cap 131, a rear end cap 132, and multiple heat exchange tubes 18. A water inlet 17 is provided at the top of the shell body. The front tube sheet 121 and the rear tube sheet 122 are located at both ends of the shell body. Multiple heat exchange tubes 18 are located between the front tube sheet 121 and the rear tube sheet 122. The front tube sheet 121, the rear tube sheet 122, and the multiple heat exchange tubes 18 form a heat exchange channel. The front end cap 131 is located on the front tube sheet 121 and forms a steam inlet 14 and a condensate outlet 15. The rear end cap 132 is located on the rear tube sheet 122.

[0034] The main body, front tube sheet 121, rear tube sheet 122, front end cap 131, and rear end cap 132 are made of high-temperature and high-pressure resistant materials, such as high-temperature resistant steel or copper alloy, to adapt to high-temperature and high-pressure operating conditions. All joints use flange sealing design to ensure system tightness and prevent leakage. The inner diameter of the shell body 11 is between 0.5 and 1.2 m, and the length is between 2 and 6 m.

[0035] The outer diameter of the heat exchange tube 18 is limited to the range of 16-25mm, and the tube wall thickness is designed to be in the range of 0.8-1.2mm. The tube body material is selected from austenitic stainless steel grade 304 or 316L to have dual characteristics of resistance to high temperature oxidation and media corrosion. Multiple heat exchange tubes 18 are assembled between the front tube sheet 121 and the rear tube sheet 122 in a composite form that includes U-shaped bend structure and straight tube multi-pass arrangement by mechanical fixing. The return heat exchange unit group forms a preset inclination angle with the tube bundle axis as the reference. This inclination angle structure makes the return tube section form a downward gradient along the medium flow direction, thereby using gravitational potential energy to promote the directional migration of condensate.

[0036] Please see Figure 3 The distributor 20 has multiple distributing holes 21 with a diameter ranging from 0.5 to 2 mm, a spacing between holes ranging from 10 to 30 mm, and a drip rate of 1 to 10 L / m²·min. Through these distributing holes 21, water drips evenly onto the surface of the heat exchange tube 18, forming a falling film evaporation and improving heat exchange efficiency. Simultaneously, the water flow rate can be adjusted via a flow control device to ensure the uniformity of the water film and the high efficiency of heat exchange.

[0037] The swirl nozzle 32 includes a valve core and an atomizing chamber. Liquid creates a vortex effect through the spiral grooves on the outer surface of the valve core, and is then atomized into tiny droplets in the atomizing chamber. When ejected through the nozzle, the water flow is atomized into droplets with a particle size of 0.1–0.5 mm, spraying onto the bottom or side areas of the heat exchange tube. This device prevents the formation of dry spots and maintains the uniformity of the water film on the surface of the heat exchange tube 18.

[0038] Furthermore, in one embodiment of the present invention, please refer to... Figure 1The mechanical swirl-type liquid replenishment device includes multiple swirl nozzles 32, which are spaced apart along the length of the shell. A connecting pipe connects the liquid collecting pump 31 to the multiple swirl nozzles 32. Through the rational arrangement of the multiple swirl nozzles 32, the entire heat exchange area can be covered more effectively, replenishing the water film lost due to evaporation in a timely manner. This ensures that the surface of the heat exchange tube 18 is always in a good heat exchange state, reducing the formation of dry spots, thereby improving the heat exchange performance and operational stability of the condenser.

[0039] Specifically, in one embodiment of the present invention, the housing is equipped with a liquid level sensor, which is located at the bottom of the front tube sheet 121. The liquid level sensor can detect changes in liquid level in real time, and the liquid level should be maintained between 10% and 90% of the height of the collecting pump 31. When the liquid level is lower than the minimum value, the collecting pump 31 is turned off; when the liquid level is higher than the maximum value, the water inlet 17 is closed.

[0040] Furthermore, in one embodiment of the present invention, please refer to... Figure 1 The top of the shell is provided with multiple water inlets 17, which are spaced apart along the length of the shell. Cooling water enters the shell through the multiple water inlets 17 and is then transmitted to the distributor 20, and then evenly distributed to the heat dissipation pipes. This allows for more even delivery of cooling water to the distributor 20, ensuring a more uniform water output from each distributing hole 21 of the distributor 20. This results in a more uniform water film on the surface of the heat dissipation pipes, improving heat exchange efficiency and effectiveness, reducing the occurrence of local dry spots, and further enhancing heat exchange performance.

[0041] Specifically, in one embodiment of the present invention, please refer to... Figure 1 The bottom of the casing is equipped with a drain outlet 16, which contains a control valve. Under normal operating conditions, the drain outlet 16 remains closed and will not affect the normal operation of the equipment. When the equipment requires internal inspection, cleaning, or maintenance, the valve can be opened to smoothly drain the accumulated water and sediment inside the casing.

[0042] To detect the state of the heat exchange tube 18, in one embodiment of the present invention, an acoustic emission sensor is provided inside the housing, and multiple temperature sensors are provided at intervals on each heat exchange tube 18. The temperature sensors can be high-temperature thermocouples or thermistors. The acoustic emission sensor and the temperature sensors work together to identify the location of the dry spots, thereby activating the corresponding swirling nozzle 32 to suppress the dry spots.

[0043] In an embodiment of the invention, high-temperature refrigerant vapor enters the condenser through heat exchange tube 18. During the heat exchange process, the distributor 20 evenly distributes cooling water onto the outer surface of the heat exchange tube 18, forming a falling film evaporation layer. By precisely controlling the water flow rate, the distributor 20 ensures that the water film evenly covers the entire interior of the condenser, effectively improving heat exchange efficiency. The water film carries away heat through falling film evaporation, the vapor condenses and releases heat, and the condensate is discharged through the condensate outlet 15 at the bottom of the front end cap 131. The generated steam leaves the condenser through the gas-liquid separation device 40, where moisture is effectively separated by a multi-stage separation structure, ensuring that the dryness of the discharged steam meets the predetermined requirements. Simultaneously, any incompletely condensed moisture is recovered through a reflux system and guided back into the heat exchange process.

[0044] When the sensor detects an abnormal temperature gradient and an abnormal vibration signal spectrum, it indicates the presence of dry spots. If a rapid increase in local temperature or vibration signal is predicted, dry spot detection can be triggered in advance. When the dry spot impact is small, the redistribution device activates a maintenance mode, with the corresponding area's vortex nozzles 32 operating at a low flow rate or spraying intermittently to maintain bottom water circulation and slight atomization, saving energy and meeting general liquid distribution needs. When several spots are identified or predicted to reach a threshold, the suppression mode is immediately switched, increasing the frequency of the collection pump 31 to increase the spray flow rate, quickly wetting the outside of the heat dissipation tubes and significantly eliminating dry spots. During system operation, continuous liquid level monitoring prevents the collection pump 31 from running dry due to low liquid levels, which could lead to wear on parts or burnout of the collection pump 31. When the liquid level is too high, the inlet is automatically closed to ensure the liquid level returns to the normal range. Through the dynamic prediction and graded spraying working mode of the mechanical vortex redistribution function, the dry spot area can be maintained below 5%, and it is quickly eliminated within 10 to 30 seconds, ensuring the condenser maintains optimal heat exchange under different loads and temperatures. The specific workflow is as follows: Figure 4 As shown.

[0045] Specifically, temperature gradient assessment is used to ensure uniform heat transfer during the condenser heat exchange process. The temperature change is calculated using the gradient calculation formula ΔT / Δx=(T1−T2) / (x1−x2), where T1 and T2 are the temperatures at two measurement points, and x1 and x2 are the relative positions of the measurement points. An excessively high temperature gradient may indicate the presence of dry spots in certain areas. A normal temperature gradient is one where the temperature gradient change does not exceed 2°C / m; if the temperature gradient change is greater than 2°C / m, it is marked as a suspected dry spot.

[0046] Spectrum analysis determines the presence of dry spots by monitoring the frequency changes of vibration signals transmitted from the surface of heat exchanger tube 18 via an acoustic emission sensor. The sensor collects signals and transmits them to a data acquisition system at a sampling frequency of 1 kHz. The signal is then subjected to a Fourier transform using spectrum analysis software, converting it into a spectrum graph and calculating the percentage of spectral fluctuation. A spectral fluctuation of less than 5% indicates stable condenser operation. When the spectral fluctuation is greater than 5% but less than 10%, it indicates the presence of dry spots within the condenser with a relatively small impact, and a maintenance mode is activated. When the spectral fluctuation is greater than 10%, the dry spot impact is considered significant, and a suppression mode is activated.

[0047] Liquid level monitoring is used to determine the normal circulation and discharge of liquid inside the condenser. A liquid level sensor is installed in the lower half of the front tube sheet 121 to monitor liquid level changes in real time. The liquid level should be maintained between 10% and 90% of the height of the collecting pump 31. When the liquid level is below the minimum value, the collecting pump 31 shuts off; when the liquid level is above the maximum value, the system automatically closes the inlet. An alarm indicator light illuminates in both cases.

[0048] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical cyclone replenishment, characterized in that, include: The shell has a heat exchange channel formed inside it, and the shell is provided with a steam inlet and a condensate outlet communicating with the heat exchange channel. The top of the shell is provided with a water inlet. A liquid distributor is disposed inside the housing and near the water inlet, and the liquid distributor has multiple liquid distribution holes. A mechanical cyclone replenishment device, comprising a liquid collecting pump, a cyclone nozzle, and a connecting pipe, wherein the liquid collecting pump and the cyclone nozzle are disposed on the inner bottom wall of the housing, and the connecting pipe connects the liquid collecting pump and the cyclone nozzle; A gas-liquid separation device, wherein the gas-liquid separation device is disposed at the top of the housing; The shell includes a shell body, a front tube sheet, a rear tube sheet, a front end cap, a rear end cap, and multiple heat exchange tubes. The water inlet is provided at the top of the shell body. The front tube sheet and the rear tube sheet are located at both ends of the shell body. The multiple heat exchange tubes are located between the front tube sheet and the rear tube sheet, forming the heat exchange channel. The front end cap is located on the front tube sheet and forms the steam inlet and the condensate outlet. The rear end cap is located on the rear tube sheet. Each of the heat exchange tubes is equipped with multiple temperature sensors spaced apart; An acoustic emission sensor is installed inside the housing; The temperature change is calculated using the gradient calculation formula ΔT / Δx=(T1-T2) / (x1-x2), where T1 and T2 are the temperatures of two measurement points, and x1 and x2 are the relative positions of the measurement points. When ΔT / Δx is greater than 2℃ / m, the acoustic emission sensor collects the signal and transmits it to the data acquisition system. The sampling frequency is 1kHz. The signal is Fourier transformed by the spectrum analysis software and converted into a spectrum graph. The spectrum fluctuation is calculated. When the spectrum fluctuation is greater than 5% but less than 10%, the maintenance mode is activated; when the spectrum fluctuation is greater than 10%, the suppression mode is activated.

2. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical vortex replenishment as described in claim 1, characterized in that, The mechanical swirling liquid replenishment device includes a plurality of swirling nozzles, which are spaced apart along the length of the housing. The connecting pipe connects the liquid collecting pump and the plurality of swirling nozzles.

3. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical vortex replenishment as described in claim 1, characterized in that, The swirl nozzle includes a valve core and an atomizing chamber that are connected to each other.

4. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical vortex replenishment as described in claim 1, characterized in that, A liquid level sensor is installed inside the housing.

5. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical vortex replenishment as described in claim 1, characterized in that, The top of the shell is provided with a plurality of water inlets, which are spaced apart along the length of the shell.

6. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical vortex replenishment as described in claim 1, characterized in that, The bottom of the housing is provided with a drain outlet, and a control valve is provided inside the drain outlet.

7. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical vortex replenishment as described in claim 1, characterized in that, The diameter of the liquid separating orifice is d, where 0.5mm ≤ d ≤ 2.0mm.

Images