High-temperature steam straight-out shell-and-tube condenser with falling film evaporation and mechanical rotational flow liquid supplementing functions

Abstract

The invention discloses a falling film evaporation and mechanical rotational flow liquid supplementing high-temperature steam direct outlet shell-and-tube condenser, and relates to the technical field of condensers, the falling film evaporation and mechanical rotational flow liquid supplementing high-temperature steam direct outlet shell-and-tube condenser comprises a shell, a liquid distributor, a mechanical rotational flow liquid supplementing device and a gas-liquid separation device; a heat exchange channel is formed in the shell, the shell is provided with a steam inlet and a condensate outlet which are communicated with the heat exchange channel, and a water injection opening is formed in the top end of the shell; the liquid distributor is arranged in the shell and is close to the water injection port, and a plurality of liquid distribution holes are formed in the liquid distributor; the mechanical rotational flow liquid supplementing device comprises a liquid collecting pump, a rotational flow nozzle and a connecting pipe, the liquid collecting pump and the rotational flow nozzle are arranged on the inner bottom wall of the shell, and the connecting pipe is connected with the liquid collecting pump and the rotational flow nozzle; the gas-liquid separation device is arranged at the top of the shell; according to the technical scheme, the heat exchange efficiency can be improved, and meanwhile, bottom accumulated liquid is recycled to restrain the dry spot phenomenon.

Description

Technical Field

[0001] The present invention relates to the technical field of condensers, and in particular to a high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment. Background Art

[0002] Steam is widely regarded as an ideal heat carrier due to its high latent heat and convenient regulation performance. In the existing technology, high-temperature heat pumps are usually used to achieve steam supply. In the high-temperature heat pump system, the condenser is a key heat exchange component, and its function is to allow the external cooling fluid to absorb the heat of the refrigerant vapor, thereby condensing the refrigerant into liquid. Shell and tube condensers are widely used due to their simple structure, stable operation and wide applicability in high temperature and high pressure situations. If falling film evaporation is used in a shell and tube condenser, the liquid can be distributed in the form of a thin film and flow along the outer wall of the tube. By absorbing the heat in the tube, the phase change is completed, achieving the purpose of efficient heat exchange and low power consumption; however, the shell and tube condenser is prone to dry spots and liquid accumulation at the bottom during use. Summary of the Invention

[0003] The main purpose of the present invention is to propose a high-temperature steam direct-outlet shell and tube condenser with falling film evaporation and mechanical swirl liquid replenishment, aiming to improve the heat exchange efficiency and at the same time recycle the bottom accumulated liquid to suppress the dry spot phenomenon.

[0004] To achieve the above-mentioned purpose, the present invention proposes a high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment, comprising: a shell having a heat exchange channel formed therein, a steam inlet and a condensate outlet in communication with the heat exchange channel, and a water inlet at the top of the shell; a liquid distributor, the liquid distributor being disposed in the housing and close to the water inlet, the liquid distributor being formed with a plurality of liquid separation holes; A mechanical swirl fluid replenishing device, comprising a liquid collecting pump, a swirl nozzle, and a connecting pipe, wherein the liquid collecting pump and the swirl nozzle are arranged on the inner bottom wall of the housing, and the connecting pipe connects the liquid collecting pump and the swirl nozzle; A gas-liquid separation device is arranged on the top of the shell.

[0005] In one embodiment, the mechanical swirl fluid replenishing device includes a plurality of swirl nozzles, which are spaced apart along the length direction of the shell, and the connecting pipe connects the liquid collecting pump and the plurality of swirl nozzles.

[0006] In one embodiment, it is characterized in that the swirl nozzle includes a valve core and an atomization chamber that are connected.

[0007] In one embodiment, it is characterized in that a liquid level sensor is provided in the housing.

[0008] In one embodiment, it is characterized in that a plurality of water injection ports are provided at the top end of the shell, and the plurality of water injection ports are spaced apart along the length direction of the shell.

[0009] In one embodiment, the shell includes a shell body, a front tube plate, a rear tube plate, a front head, a rear head and a plurality of heat exchange tubes, the water injection port is provided at the top of the shell body, the front tube plate and the rear tube plate are provided at both ends of the shell body, the plurality of heat exchange tubes are provided between the front tube plate and the rear tube plate, the front tube plate, the rear tube plate and the plurality of heat exchange tubes form the heat exchange channel, the front head is provided on the front tube plate, the front head forms the steam inlet and the condensate outlet, and the rear head is provided on the rear tube plate.

[0010] In one embodiment, each of the heat exchange tubes is provided with a plurality of temperature sensors arranged at intervals.

[0011] In one embodiment, an acoustic emission sensor is disposed in the housing.

[0012] In one embodiment, a water outlet is provided at the bottom end of the shell, and a control valve is provided in the water outlet.

[0013] In one embodiment, the diameter of the liquid separation hole is d, 0.5 mm ≤ d ≤ 2.0 mm.

[0014] In the technical solution of the present invention, high-temperature refrigerant vapor can enter the heat exchange channel through the steam inlet of the shell, condense and release heat in the heat exchange channel, and eventually be discharged from the condensate outlet in the form of condensed water. Cooling water enters the shell through the water inlet and then evenly contacts the heat exchange channel through multiple liquid separation holes on the liquid distributor, forming falling film evaporation, increasing the heat exchange area, improving heat exchange efficiency, and enabling more efficient heat transfer and absorption. The gas-liquid separation device can separate the generated steam, making the discharged steam purer and drier, meeting usage requirements and improving steam quality. At the same time, the liquid collection pump and swirl nozzle are installed on the bottom wall of the shell to centrifugally atomize the water deposited at the bottom of the shell and spray it upward, allowing the accumulated liquid at the bottom to be recycled, improving the uniformity of the water film, and effectively suppressing dry spots. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0016] Figure 1 A schematic structural diagram of an embodiment of a high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment provided by the present invention; Figure 2 for Figure 1 sectional view of Figure 3 It is a structural schematic diagram of an embodiment of a liquid distributor; Figure 4 This is a working diagram of swirl liquid replenishment in an embodiment of a high-temperature steam direct-outlet shell and tube condenser with falling film evaporation and mechanical swirl liquid replenishment provided by the present invention.

[0017] Description of Figure Numbers: 11. Shell body; 121. Front tube sheet; 122. Rear tube sheet; 131. Front head; 132. Rear head; 14. Steam inlet; 15. Condensate outlet; 16. Drain port; 17. Water injection port; 18. Heat exchange tube; 20. Liquid distributor; 21. Liquid separation hole; 31. Liquid collecting pump; 32. Swirl nozzle; 40. Gas-liquid separation device.

[0018] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0021] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0022] The present invention provides a high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment.

[0023] See also 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 liquid replenishment includes a shell, a liquid distributor 20, a mechanical cyclone liquid replenishment device and a gas-liquid separation device 40; a heat exchange channel is formed in the shell, and the shell is provided with a steam inlet 14 and a condensate outlet 15 connected to the heat exchange channel, and a water injection port 17 is provided at the top of the shell; the liquid distributor 20 is arranged in the shell and is arranged close to the water injection port 17, and the liquid distributor 20 is formed with a plurality of liquid separation holes 21; the mechanical cyclone liquid 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 arranged 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 arranged at the top of the shell.

[0024] In the technical solution of the present 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 as condensed water through the condensate outlet 15. Cooling water enters the shell through the water inlet 17 and then evenly contacts the heat exchange channel through the multiple liquid separation holes 21 on the liquid distributor 20, forming falling film evaporation, increasing the heat exchange area, improving heat exchange efficiency, and enabling more efficient heat transfer and absorption. The gas-liquid separation device 40 can separate the generated steam, making the discharged steam purer and drier, meeting usage requirements and improving steam quality. At the same time, the liquid collection pump 31 and swirl nozzle 32 are located on the bottom wall of the shell, centrifugally atomizing the water deposited at the bottom of the shell and spraying it upward, allowing the accumulated liquid at the bottom to be recycled, improving the uniformity of the water film, and effectively suppressing dry spots.

[0025] 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 head 131, a rear head 132 and a plurality of 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 arranged at both ends of the shell body. A plurality of heat exchange tubes 18 are arranged between the front tube sheet 121 and the rear tube sheet 122. The front tube sheet 121, the rear tube sheet 122 and the plurality of heat exchange tubes 18 form a heat exchange channel. The front head 131 is arranged on the front tube sheet 121. The front head 131 forms a steam inlet 14 and a condensate outlet 15. The rear head 132 is arranged on the rear tube sheet 122.

[0026] The main body, front tube sheet 121, rear tube sheet 122, front head 131, and rear head 132 are constructed of high-temperature, high-pressure-resistant materials, such as high-temperature steel or copper alloy, to accommodate high-temperature and high-pressure operating conditions. Flange seals are used at all joints to ensure a leak-proof system. The shell body 11 has an inner diameter between 0.5 and 1.2 m and a length between 2 and 6 m.

[0027] 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 material is selected from austenitic stainless steel grades 304 or 316L to have the dual characteristics of resistance to high-temperature oxidation and medium corrosion; multiple heat exchange tubes 18 are assembled between the front tube sheet 121 and the rear tube sheet 122 by mechanical fixing in a composite form including a U-shaped bend structure and a straight tube multi-flow arrangement; the return heat exchange unit group forms a preset inclination angle with the axis of the tube bundle as the reference. This inclination structure causes the return pipe section to form a descending gradient along the direction of medium flow, thereby utilizing gravitational potential energy to promote the directional migration of condensate.

[0028] See also Figure 3 The liquid distributor 20 has multiple liquid distribution holes 21 with a diameter ranging from 0.5 to 2 mm, a spacing of 10 to 30 mm, and a dripping intensity of 1 to 10 L / m²·min. Through these distribution holes 21, water drips evenly onto the surface of the heat exchange tubes 18, forming a falling film evaporation pattern and improving heat exchange efficiency. A flow control device can also be used to adjust the water flow rate, ensuring uniformity of the water film and efficient heat exchange.

[0029] The swirl nozzle 32 comprises a valve core and an atomizing chamber. The liquid flows through the spiral grooves on the outer surface of the valve core, creating a vortex effect. The liquid is then atomized into tiny droplets in the atomizing chamber. When discharged through the nozzle, the water is atomized into droplets with a diameter of 0.1 to 0.5 mm, which are sprayed onto the bottom or side areas of the heat exchange tube. This device prevents the formation of dry spots and maintains a uniform water film on the surface of the heat exchange tube 18.

[0030] Further, in one embodiment of the present invention, please refer to Figure 1The mechanical swirl rehydration device includes multiple swirl nozzles 32 spaced apart along the length of the housing, with connecting pipes connecting the liquid collection pump 31 and the multiple swirl nozzles 32. The rational layout of the multiple swirl nozzles 32 effectively covers the entire heat exchange area, promptly replenishing the water film reduced by evaporation, ensuring that the surface of the heat exchange tubes 18 is always in a good heat exchange state, reducing the formation of dry spots, and thus improving the heat exchange performance and operational stability of the condenser.

[0031] Specifically, in one embodiment of the present invention, the housing is equipped with a liquid level sensor located at the bottom of the front tube plate 121. This sensor can detect changes in the liquid level in real time. The liquid level should be maintained between 10% and 90% of the height of the liquid collecting pump 31. When the liquid level falls below the minimum value, the liquid collecting pump 31 is shut off; when the liquid level rises above the maximum value, the water inlet 17 is closed.

[0032] Further, in one embodiment of the present invention, please refer to Figure 1 The top of the housing is provided with multiple water inlets 17, spaced apart along the length of the housing. Cooling water enters the housing through these inlets 17 and is then transferred to the liquid distributor 20 for even distribution to the heat pipes. This ensures a more uniform delivery of cooling water to the liquid distributor 20, ensuring a more uniform water output from each of the liquid distribution holes 21 in the liquid distributor 20. This creates a more uniform water film on the surface of the heat pipes, improving heat exchange efficiency and effectiveness, reducing the occurrence of localized dry spots, and further enhancing heat exchange performance.

[0033] Specifically, in one embodiment of the present invention, please refer to Figure 1 The bottom of the housing is provided with a drain port 16, which contains a control valve. Under normal operating conditions, drain port 16 remains closed and does not affect the normal operation of the equipment. When the equipment requires internal inspection, cleaning, or maintenance, the valve can be opened to drain the accumulated water and sediment in the housing.

[0034] To monitor the status of the heat exchange tubes 18, in one embodiment of the present invention, an acoustic emission sensor is installed within the housing, and multiple temperature sensors are spaced apart on each heat exchange tube 18. The temperature sensors can be high-temperature thermocouples or thermistors. The acoustic emission and temperature sensors work together to identify the location of dry spots, thereby activating the corresponding swirl nozzles 32 and suppressing dry spots.

[0035] In an embodiment of the present invention, high-temperature refrigerant vapor enters the condenser through the heat exchange tube 18. During the heat exchange process, the liquid distributor 20 evenly distributes the cooling water to the outer surface of the heat exchange tube 18 to form a falling film evaporation layer. By precisely controlling the water flow rate, the liquid distributor 20 ensures that the water film evenly covers the entire interior of the condenser, effectively improving the heat exchange efficiency. The water film takes away heat through falling film evaporation, the steam condenses and releases heat, and the condensate is discharged through the condensate outlet 15 at the bottom of the front head 131. The generated steam leaves the condenser through the gas-liquid separation device 40, and the water is effectively separated by the multi-stage separation structure to ensure that the dryness of the discharged steam meets the predetermined requirements. At the same time, the water that is not completely condensed is recovered through the reflux system and guided back to the heat exchange process.

[0036] When the sensor detects an abnormal temperature gradient and an abnormal vibration signal spectrum, it is considered that there is a dry spot; if it is predicted that the local temperature or vibration signal is rising rapidly, the dry spot detection can also be triggered in advance. When the dry spot has a small impact, the redistribution device turns on the maintenance mode, and the mechanical swirl nozzle 32 in the corresponding area only works at a lower flow rate or sprays intermittently to maintain the bottom water circulation and slight atomization, which is energy-saving and meets the general liquid distribution needs. When a number of spot identifications or predictions reach the threshold, the suppression mode is immediately switched to increase the frequency of the liquid collection pump 31 to increase the injection flow rate, infiltrating the outside of the heat dissipation pipe in a short time, and greatly eliminating the dry spot. During the operation of the system, the liquid level is continuously monitored to avoid idling of the liquid collection pump 31 due to too low a liquid level, resulting in wear parts or burning of the liquid collection pump 31; when the liquid level is too high, the water inlet is automatically closed to ensure that the liquid level returns to the normal range. Through the dynamic prediction + graded spray working mode of the mechanical swirl redistribution function, the dry spot area can be maintained below 5%, and it can be quickly eliminated within 10 to 30 seconds to ensure that the condenser maintains the best heat exchange state under different load and temperature conditions. The specific work flow is as follows Figure 4 shown.

[0037] Specifically, temperature gradient assessment ensures 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 the two measurement points, and x1 and x2 are the relative positions of the measurement points. Excessively high temperature gradients may indicate the presence of dry spots in certain areas. A normal temperature gradient is defined as a change of no more than 2°C / m; a change greater than 2°C / m is flagged as a suspected dry spot.

[0038] Spectrum judgment is to determine whether dry spots have occurred by monitoring the frequency changes of the vibration signal on the surface of the heat exchange tube 18 transmitted back by the acoustic emission sensor. The sensor collects the signal and transmits it to the data acquisition system with a sampling frequency of 1kHz. The signal is Fourier transformed by spectrum analysis software, converted into a spectrum diagram, and the percentage of spectrum fluctuation is calculated. The spectrum fluctuation of the vibration signal should be less than 5%, indicating that the condenser is operating stably. When the spectrum fluctuation is greater than 5% but less than 10%, it indicates that dry spots exist in the condenser and the impact is small, and the maintenance mode is activated; when the spectrum fluctuation is greater than 10%, it is considered that the dry spot has a large impact, and the suppression mode is activated.

[0039] Liquid level monitoring is used to determine the proper circulation and drainage of the liquid within the condenser. A liquid level sensor, mounted on the lower half of the front tube sheet 121, monitors liquid level changes in real time. The liquid level should be maintained between 10% and 90% of the height of the liquid collection pump 31. When the liquid level falls below the minimum value, the liquid collection pump 31 shuts down. When the liquid level rises above the maximum value, the system automatically closes the water inlet, illuminating the alarm indicator in both cases.

[0040] 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 transformation made by utilizing the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in 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 swirl liquid replenishment, characterized in that: include: a shell having a heat exchange channel formed therein, a steam inlet and a condensate outlet in communication with the heat exchange channel, and a water inlet at the top of the shell; a liquid distributor, the liquid distributor being disposed in the housing and close to the water inlet, the liquid distributor being formed with a plurality of liquid separation holes; A mechanical swirl fluid replenishing device, comprising a liquid collecting pump, a swirl nozzle, and a connecting pipe, wherein the liquid collecting pump and the swirl nozzle are arranged on the inner bottom wall of the housing, and the connecting pipe connects the liquid collecting pump and the swirl nozzle; A gas-liquid separation device is arranged on the top of the shell.

2. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment according to claim 1, characterized in that: The mechanical swirl fluid replenishing device includes a plurality of swirl nozzles, which are arranged at intervals along the length direction of the shell, and the connecting pipe connects the liquid collection pump and the plurality of swirl nozzles.

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

4. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment according to claim 1, characterized in that: A liquid level sensor is arranged in the shell.

5. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment according to claim 1, characterized in that: The top of the shell is provided with a plurality of water injection ports, and the plurality of water injection ports are arranged at intervals along the length direction of the shell.

6. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment according to claim 1, characterized in that: The shell includes a shell body, a front tube plate, a rear tube plate, a front head, a rear head and a plurality of heat exchange tubes. The water injection port is provided at the top of the shell body. The front tube plate and the rear tube plate are provided at both ends of the shell body. The plurality of heat exchange tubes are provided between the front tube plate and the rear tube plate. The front tube plate, the rear tube plate and the plurality of heat exchange tubes form the heat exchange channel. The front head is provided on the front tube plate. The front head forms the steam inlet and the condensate outlet. The rear head is provided on the rear tube plate.

7. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment according to claim 6, characterized in that: Each of the heat exchange tubes is provided with a plurality of temperature sensors arranged at intervals.

8. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment according to claim 1, characterized in that: An acoustic emission sensor is arranged in the shell.

9. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment according to claim 1, characterized in that: A water outlet is provided at the bottom end of the shell, and a control valve is provided in the water outlet.

10. The high-temperature steam direct-outlet shell-and-tube condenser with falling film evaporation and mechanical swirl liquid replenishment according to claim 1, characterized in that: The aperture of the liquid separation hole is d, 0.5mm≤d≤2.0mm.

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