High-efficiency throttling-controllable liquid membrane evaporator and operation method

Abstract

The application provides a high-efficiency throttling-controllable liquid separation type liquid membrane evaporator and an operation method, comprising a circulating working medium pump, an electric regulating valve, a liquid level sensor, a liquid membrane evaporator and a liquid separator. The system fully utilizes the unique structural design and precise control mechanism to realize the high efficiency and controllability of liquid separation and liquid membrane formation, thereby greatly improving the evaporation heat exchange efficiency of the evaporator. The evaporator effectively improves the evaporation heat exchange efficiency, reduces energy consumption, and at the same time guarantees the stability and reliability of system operation. In addition, the evaporator can be widely applied to the industries requiring liquid working medium evaporation, such as chemical industry, pharmaceutical industry and food industry, and can adapt to the liquid working medium evaporation demand under different environments, and has wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of split-liquid film evaporators, and more particularly to a high-efficiency split-liquid film evaporator with throttling control and its operating method. Background Technology

[0002] In many fields involving the evaporation of liquid working fluids, such as chemical engineering and food processing, traditional shell-and-tube evaporators have long been widely used. However, traditional liquid working fluid evaporation technologies often suffer from low efficiency and poor stability. With the continuous development of industry, the demand for high-efficiency evaporation technologies is becoming increasingly urgent.

[0003] In the evaporation process of a liquid working fluid, the flow of the liquid working fluid within the tube is crucial. This is especially true for split-film evaporators, where the design of the liquid distributor and the flow state of the liquid working fluid within the evaporation tube directly determine the evaporator's performance and lifespan. Uneven distribution of the liquid working fluid can lead to interruptions in the liquid film within the evaporation tube, resulting in localized dry evaporation. This localized dry evaporation not only reduces the evaporator's efficiency but also easily causes overheating of the tube walls, potentially leading to scaling. Scale not only increases thermal resistance and reduces heat transfer efficiency but can also corrode the pipes, further affecting the flow of the liquid working fluid and the evaporator's performance. Furthermore, an excessively thick liquid film can also significantly reduce the overall evaporation efficiency of the evaporator. Summary of the Invention

[0004] In view of the problems existing in the background art, the purpose of this invention is to provide a high-efficiency liquid film evaporator with throttling control and its operation method, which can effectively improve the uneven distribution of liquid working fluid, realize uniform and stable liquid film flow on the inner wall of the evaporation tube, and at the same time, the evaporator not only has high heat transfer efficiency, but also minimizes the occurrence of scaling problems; it can precisely control the throttling, thereby achieving precise control of liquid film thickness; in addition, it can adapt to the evaporation requirements of various working conditions and materials, thereby improving the evaporation efficiency and service life of the evaporator.

[0005] To achieve the above-mentioned technical features, the present invention aims to provide a high-efficiency, flow-controlled, liquid-separating liquid film evaporator, comprising a liquid film evaporator, wherein a liquid separator is provided inside the liquid film evaporator, the liquid separator being connected to a liquid working fluid inlet via an electric regulating valve; the top of the liquid film evaporator being connected to a liquid working fluid outlet; the bottom of the liquid film evaporator being connected to a liquid working fluid inlet via a circulating working fluid pump; and a liquid level sensor being provided inside the liquid film evaporator.

[0006] Preferably, the circulating working fluid pump delivers the liquid working fluid to the electric regulating valve in a timely and accurate manner based on the signal fed back by the liquid level sensor; The electric regulating valve can dynamically adjust its opening to achieve precise control of the liquid working fluid flow rate, ensuring that the liquid working fluid can enter the distributor at a suitable flow rate, so that the liquid working fluid is evenly distributed and forms a controllable liquid film.

[0007] Preferably, the electric regulating valve can dynamically adjust its opening degree according to the liquid level change detected by the liquid level sensor, so as to achieve precise control of the liquid working fluid flow rate; When the liquid level is higher than the initial set value and continues to rise, the liquid film is too thick. At this time, the flow rate is controlled by reducing the opening of the electric regulating valve to control the liquid film thickness and maintain the ultra-high heat transfer coefficient under forced liquid film convection heat transfer. When the liquid level is lower than the initial set value and continues to decrease, the liquid film is too thin or the wall may even be dry and without liquid film, resulting in insufficient liquid content and deterioration of the second type of heat transfer. At this time, the opening of the electric regulating valve is increased and the flow rate of the liquid working fluid is increased to maintain a suitable liquid film thickness on the wall of the liquid film evaporator, ensuring that the evaporator wall is always in a forced liquid film convection heat transfer state and maintaining a high efficiency evaporation heat transfer coefficient. When the liquid level change is in dynamic equilibrium, the electric regulating valve maintains its current opening to keep the current liquid working fluid flow constant, thereby ensuring that the liquid film thickness on the wall of the liquid film evaporator is within a reasonable range.

[0008] Preferably, the liquid level sensor can monitor the changes in liquid level in the liquid film evaporator in real time and accurately, and feed the information back to the circulating working fluid pump and the electric regulating valve, thereby providing a basis for the working status of the circulating working fluid pump and the opening degree of the electric regulating valve.

[0009] Preferably, the upper inner wall of the liquid film evaporator is provided with an annular groove, and a certain gap is left between the annular groove and the outermost ring of the distributor; after the liquid working fluid jet enters the annular groove, it will flow down counterclockwise in a spiral direction along the inner wall of the groove. At the same time, a large number of slender inner wall groove channels are seamlessly connected at the bottom of the annular groove to increase the heat exchange area and facilitate the formation of liquid film heat exchange.

[0010] Preferably, the inner wall groove can take on a variety of different shapes, such as straight, curved, or broken lines, and the number of grooves can be flexibly set according to actual needs.

[0011] Preferably, the connection between the bottom of the annular groove and the inner wall groove channel is rounded.

[0012] Preferably, the dispenser is in the form of a disc or a spiral tube; After the liquid working fluid enters from the center, it flows out of the distributor in a counterclockwise direction. The outermost ring of the distributor is provided with multiple openings along the flow direction of the liquid working fluid. The number of openings can be adjusted according to actual application requirements, and the openings are arranged tangentially. The liquid working fluid is guided out tangentially along the circumference through the openings and falls into the annular groove on the upper inner wall of the liquid film evaporator in a spiral motion. This ensures that the liquid working fluid can be evenly distributed into the inner wall groove channel of the liquid film evaporator under the dual action of centrifugal force and gravity in the circular motion.

[0013] An operating method for a high-efficiency, flow-controlled, split-liquid film evaporator: During operation, the liquid working fluid first enters the system through an electric regulating valve; inside the distributor, the liquid working fluid rotates counterclockwise in a spiral motion, and finally exits tangentially through multiple jet nozzles set on its outermost ring. The tangentially jetted liquid working fluid will quickly and evenly splash into the annular groove on the upper inner wall of the liquid film evaporator. Then, under the action of gravity, it flows down along the slender inner wall channels inside the liquid film evaporator, forming a large number of independent liquid films with extremely high heat transfer coefficients on a large number of slender inner wall channels, which increases the heat transfer area and greatly improves the overall heat transfer coefficient of the evaporator. Meanwhile, a liquid level sensor is installed at the bottom of the liquid film evaporator to monitor the liquid level in real time. When the liquid level is too high, it indicates that the liquid film is too thick and the heat exchange efficiency is reduced. The signal is fed back to the circulating working fluid pump to pump out the liquid working fluid accumulated at the bottom of the liquid film evaporator. At the same time, the opening of the electric regulating valve is reduced to decrease the flow rate of the liquid working fluid, thereby matching the heat exchange load of the evaporator at this time, reducing the liquid film thickness, dynamically improving the heat transfer coefficient of the evaporator wall, and increasing the overall heat exchange efficiency. When the liquid level is too low, it indicates that the liquid film is too thin or even dried up, and the heat exchange efficiency is reduced. The circulating working fluid pump does not work, and the control system increases the opening of the electric regulating valve to increase the flow rate of the liquid working fluid, ensuring that a liquid film of appropriate thickness is formed on the inner wall of the liquid film evaporator, increasing the stability and continuity of the liquid film, and thus improving the overall heat exchange efficiency of the liquid film evaporator. When the liquid level is in dynamic equilibrium, the circulating working fluid pump does not work and the electric regulating valve maintains a stable opening to keep the liquid working fluid flow constant. In this way, the efficient, stable and controllable operation of the split-type liquid film evaporator is ensured, thereby achieving the ideal working state and effect.

[0014] When the flow rate is high, multiple liquid-film evaporators need to be connected in parallel to form a parallel module of liquid-film evaporators with throttling control. Under the same floor space, multiple slender liquid-film evaporators can significantly increase the liquid film area compared to a single liquid-film evaporator, thereby greatly improving the heat exchange efficiency. When the flow rate is low, the demand can be met by operating only a single liquid-film evaporator.

[0015] The present invention has the following beneficial effects: 1. This invention optimizes the design of the liquid working fluid distributor and controls the thickness of the liquid film to achieve uniform distribution and stable flow of the liquid working fluid on the inner wall of the evaporator, thereby improving the evaporation efficiency and service life of the evaporator.

[0016] 2. The evaporator of this invention not only achieves uniform distribution and stable flow of the liquid working fluid, but also significantly improves evaporation efficiency and heat transfer performance. Compared with traditional technologies, this invention not only has a reasonable structural design and is easy to operate, but it can also flexibly adjust the throttling degree and liquid separation effect according to actual needs, adapting to various complex operating conditions and demonstrating strong adaptability and versatility. Furthermore, its unique design effectively reduces equipment operating costs and maintenance difficulty, significantly improving the reliability and stability of the entire system.

[0017] 3. The present invention can dynamically adjust the opening of the electric regulating valve according to the liquid level change detected by the liquid level sensor, so as to achieve precise control of the flow rate of the liquid working fluid.

[0018] 4. This invention uses a liquid level sensor to monitor the liquid level changes in the liquid film evaporator in real time and accurately, and feeds the information back to the circulating working fluid pump and the electric regulating valve. This provides a basis for the working status of the circulating working fluid pump and the opening degree of the electric regulating valve, thereby ensuring precise control of the liquid working fluid supply and flow rate, optimizing the liquid film thickness, maintaining the efficient and stable operation of the evaporator, and ultimately achieving the goal of controllable and uniform liquid film distribution.

[0019] 5. In this invention, an annular groove is provided on the upper inner wall of the liquid film evaporator, and a certain gap is left between the annular groove and the outermost ring of the distributor. After the liquid working fluid jet enters the annular groove, it will flow down in a counterclockwise spiral along the inner wall of the groove. At the same time, a large number of slender inner wall channels are seamlessly connected at the bottom of the annular groove to increase the heat exchange area and facilitate the formation of liquid film heat exchange.

[0020] 6. This invention, by setting a spiral-shaped distributor and setting openings, ensures that the liquid working fluid obtains a large circumferential tangential velocity when flowing out. The liquid working fluid can quickly and evenly splash into the annular groove on the upper inner wall of the liquid film evaporator along these grooves. Thereafter, the liquid working fluid rotates counterclockwise and flows spirally downward in the annular groove. Finally, it enters the inner wall channel of the liquid film evaporator at the bottom of the annular groove, thereby forming a uniformly distributed descending liquid film on the inner wall channel of the evaporator.

[0021] 7. This invention uses multiple liquid film evaporators connected in parallel to form a parallel module of liquid-distributing liquid film evaporators with throttling control. Within the same floor space, multiple slender liquid film evaporators significantly increase the liquid film area compared to a single liquid film evaporator, thereby greatly improving heat exchange efficiency. At lower flow rates, operating only a single liquid film evaporator is sufficient to meet the requirements. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This is a schematic diagram of a high-efficiency liquid film evaporator with throttling control according to the present invention.

[0024] Figure 2 This is a schematic cross-sectional view of the internal structure of the liquid film evaporator of the present invention.

[0025] Figure 3 (a), (b), and (c) are schematic diagrams of the inner wall groove channel form of the liquid film evaporator of the present invention.

[0026] Figure 4 This is a schematic diagram of the structure of the disc-shaped liquid dispenser of the present invention.

[0027] Figure 5 This is a schematic diagram of the spiral tubular liquid separator structure of the present invention.

[0028] Figure 6 This is a schematic diagram of the parallel module of the liquid film evaporator with throttling control of the present invention.

[0029] In the diagram: 1. Circulating working fluid pump; 2. Electric regulating valve; 3. Liquid level sensor; 4. Liquid film evaporator; 5. Separator. Annular groove 4-1, inner wall groove channel 4-2; Opening 5-1. Detailed Implementation

[0030] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0031] Example 1: like Figure 1 As shown, a high-efficiency, throttling-controlled liquid-film evaporator includes: a circulating working fluid pump 1, an electric regulating valve 2, a liquid level sensor 3, a liquid film evaporator 4, and a distributor 5. The distributor 5 is internally located within the liquid film evaporator 4 and is connected to the liquid working fluid inlet via the electric regulating valve 2. The top of the liquid film evaporator 4 is connected to the liquid working fluid outlet. The bottom of the liquid film evaporator 4 is connected to the liquid working fluid inlet via the circulating working fluid pump 1. The liquid level sensor 3 is internally located within the liquid film evaporator 4. This system fully utilizes its unique structural design and precise control mechanism to achieve high efficiency and controllability in liquid separation and liquid film formation, thereby significantly improving the evaporator's evaporation heat exchange efficiency. This evaporator effectively improves evaporation heat exchange efficiency, reduces energy consumption, and ensures the stability and reliability of system operation. Furthermore, this evaporator can be widely used in industries requiring liquid working fluid evaporation, such as chemical, pharmaceutical, and food processing, and can adapt to the liquid working fluid evaporation needs under different environments, demonstrating broad application prospects.

[0032] Furthermore, the circulating working fluid pump 1 can deliver the liquid working fluid to the electric regulating valve 2 in a timely and accurate manner based on the signal fed back by the liquid level sensor 3. The electric regulating valve 2 can dynamically adjust its opening to achieve precise control of the liquid working fluid flow rate, ensuring that the liquid working fluid can enter the distributor 5 at a suitable flow rate, so that the liquid working fluid is evenly distributed and forms a controllable liquid film.

[0033] Furthermore, the electric regulating valve 2 can dynamically adjust its opening based on the liquid level changes detected by the liquid level sensor 3, thereby achieving precise control of the liquid working fluid flow rate. When the liquid level is higher than the initial set value and continues to rise, it indicates that the liquid film is too thick. The flow rate needs to be reduced to prevent the forced liquid film convection heat transfer from being replaced by the full liquid saturation boiling or supercooled boiling that occurs in conventional evaporators, thus reducing the overall heat transfer coefficient of the evaporator. In this case, the flow rate is controlled by reducing the opening of the electric regulating valve 2 to control the liquid film thickness and maintain the ultra-high heat transfer coefficient under forced liquid film convection heat transfer. Conversely, when the liquid level is lower than the initial set value and continues to drop, it indicates that the liquid film is too thin or even that the wall surface is dry with no liquid film, leading to deterioration of the second type of heat transfer due to insufficient liquid content. In this case, the opening of the electric regulating valve 2 should be increased to increase the liquid working fluid flow rate to maintain a suitable liquid film thickness on the wall of the liquid film evaporator 4, ensuring that the evaporator wall surface is always in a forced liquid film convection heat transfer state and maintaining a high efficiency evaporation heat transfer coefficient. When the liquid level change is in dynamic equilibrium, the electric regulating valve 2 keeps the current opening unchanged to maintain the current liquid working fluid flow rate constant, thereby ensuring that the liquid film thickness on the wall of the liquid film evaporator 4 is within a reasonable range, thus achieving the effect of controllable and uniform liquid film distribution.

[0034] Furthermore, the liquid level sensor 3 monitors the changes in liquid level within the liquid film evaporator 4 in real time and accurately, feeding the information back to the circulating working fluid pump 1 and the electric regulating valve 2. This provides a basis for the operating status of the circulating working fluid pump 1 and the opening degree of the electric regulating valve 2, thereby ensuring precise control of the liquid working fluid supply and flow rate, optimizing the liquid film thickness, maintaining the efficient and stable operation of the evaporator, and ultimately achieving the goal of controllable and uniform liquid film distribution.

[0035] Further, see Figure 2 The upper inner wall of the liquid film evaporator 4 is provided with an annular groove 4-1, which leaves a certain gap with the outermost ring of the distributor 5. After the liquid working fluid jet enters the annular groove 4-1, it will flow down in a counterclockwise spiral along the inner wall of the groove. At the same time, a large number of slender inner wall channels 4-2 are seamlessly connected to the bottom of the annular groove 4-1 to increase the heat exchange area and facilitate the formation of liquid film heat exchange.

[0036] Furthermore, the inner wall groove channel 4-2 can take various forms, as described in the appendix of this invention. Figure 3Only some specific forms are shown, while numerous other forms not illustrated exist. Those skilled in the art should understand that the working principles, extended applications, combination methods, and adjustments related to the inner wall channel 4-2 are all within the scope of this invention. Specifically, the shape of the inner wall channel 4-2 can also be straight, curved, or polygonal, and its number can be flexibly set according to actual needs. Therefore, the form of the inner wall channel 4-2 can be flexibly selected and adjusted according to different operating conditions and performance requirements. This flexible structure increases the heat exchange area, allowing the same volume of liquid working fluid to contact more of the evaporator's inner wall, thereby accelerating the heat exchange process. Furthermore, the different shapes of the inner wall channels can increase the flow path and number of passes for the liquid working fluid, increasing the residence time of the liquid working fluid in the evaporator and achieving uniform distribution and stable triggering of the liquid film, further improving heat exchange efficiency. In addition, rounding the corners at the connection between the bottom of the annular groove 4-1 and the inner wall channel 4-2 allows the liquid working medium in the annular groove 4-1 to enter the inner wall channel 4-2 area quickly and evenly, avoiding the accumulation of liquid working medium at the connection or the formation of flow obstacles.

[0037] Furthermore, the dispenser 5 can be made in the form of a disc or a spiral tube, but is not limited to these two forms, such as... Figure 4-5 As shown in the figure, it is only a simplified illustration to help explain the invention, and those skilled in the art should understand that the related working principles are all covered herein. Figure 4 For example, the distributor 5 adopts a unique counter-clockwise mosquito coil shape design. After the liquid working fluid enters from the center, it flows out of the distributor 5 in a counter-clockwise direction. The outermost ring of the distributor 5 is provided with multiple openings 5-1 along the flow direction of the liquid working fluid. The number of openings can be adjusted according to actual application requirements, and the openings 5-1 are arranged tangentially. The main function of these openings is to guide the liquid working fluid to jet out tangentially along the circumference and fall into the annular groove 4-1 on the upper inner wall of the liquid film evaporator 4 in a spiral motion, ensuring that the liquid working fluid can be evenly distributed into the inner wall groove channel 4-2 of the liquid film evaporator 4 under the dual action of centrifugal force and gravity of the circumferential motion. Because the liquid working fluid acquires a large tangential velocity during outflow, it can quickly and evenly splash along these grooves into the annular groove 4-1 on the upper inner wall of the liquid film evaporator 4. Thereafter, the liquid working fluid rotates counterclockwise and spirals downward within the annular groove. Finally, it enters the inner wall channel 4-2 inside the liquid film evaporator 4 at the bottom of the annular groove, thereby forming a uniformly distributed descending liquid film on the inner wall channel 4-2 of the evaporator.

[0038] Example 2: like Figure 1This invention provides a method for operating a high-efficiency liquid film evaporator with throttling control: During operation, the liquid working fluid first enters the system through the electric regulating valve 2; inside the distributor 5, the liquid working fluid rotates counterclockwise in a spiral motion and finally exits tangentially through multiple jet nozzles set on its outermost ring. The tangentially jetted liquid working fluid will quickly and evenly splash into the annular groove 4-1 on the upper inner wall of the liquid film evaporator 4, and then flow down along the slender inner wall groove channel 4-2 inside the liquid film evaporator 4 under the action of gravity. A large number of independent liquid films with extremely high heat transfer coefficients are formed on the numerous slender inner wall groove channels 4-2, which increases the heat transfer area and greatly improves the overall heat transfer coefficient of the evaporator. Meanwhile, the liquid level sensor 3 is installed at the bottom of the liquid film evaporator 4 to monitor the liquid level height accumulated in the evaporator in real time. When the liquid level is too high, it indicates that the liquid film is too thick and the heat exchange efficiency is reduced. The signal is fed back to the circulating working fluid pump 1 to pump out the liquid working fluid accumulated at the bottom of the liquid film evaporator 4. At the same time, the opening of the electric regulating valve 2 is reduced to reduce the flow rate of the liquid working fluid, thereby matching the heat exchange load of the evaporator at this time, reducing the liquid film thickness, dynamically improving the heat transfer coefficient of the evaporator wall, and increasing the overall heat exchange efficiency. When the liquid level is too low, it indicates that the liquid film is too thin or even dried up, and the heat exchange efficiency is reduced. The circulating working fluid pump 1 does not work, and the control system will increase the opening of the electric regulating valve 2 to increase the flow rate of the liquid working fluid, ensuring that a liquid film of appropriate thickness is formed on the inner wall of the liquid film evaporator 4, increasing the stability and continuity of the liquid film, and thus improving the overall heat exchange efficiency of the liquid film evaporator 4. When the liquid level is in dynamic equilibrium, the circulating working fluid pump 1 does not work and the electric regulating valve 2 maintains a stable opening to keep the liquid working fluid flow constant. In this way, the efficient, stable and controllable operation of the split liquid film evaporator is ensured, thereby achieving the ideal working state and effect.

[0039] Example 3: See Figure 6 When the flow rate is high, multiple liquid film evaporators need to be connected in parallel to form a parallel module of liquid film evaporators with throttling control. In this way, within the same floor space, multiple slender liquid film evaporators can significantly increase the liquid film area compared to a single liquid film evaporator, thereby greatly improving heat exchange efficiency. When the flow rate is low, operating only a single liquid film evaporator is sufficient to meet the requirements.

[0040] Although the invention has been described above in conjunction with the accompanying drawings, the invention is not limited to the specific embodiments described. Furthermore, the illustration of individual devices or elements in this embodiment is merely for the convenience of describing the invention and simplifying the description. In practice, these devices or elements can be combined, expanded, or adjusted as needed. Therefore, those skilled in the art should understand that any modifications or variations made without departing from the technical solution of the invention are within the scope of protection of the invention.

Claims

1. A high-efficiency throttling-controllable liquid-liquid membrane evaporator, characterized in that, The system includes a liquid film evaporator (4), which has a liquid separator (5) inside. The liquid separator (5) is connected to the liquid working fluid inlet via an electric regulating valve (2). The top of the liquid film evaporator (4) is connected to the gaseous working fluid outlet. The bottom of the liquid film evaporator (4) is connected to the liquid working fluid inlet via a circulating working fluid pump (1). The liquid film evaporator (4) has a liquid level sensor (3) inside. The liquid level sensor (3) can monitor the liquid level change in the liquid film evaporator (4) in real time and feed the information back to the circulating working fluid pump (1) and the electric regulating valve (2), thereby providing a basis for the working status of the circulating working fluid pump (1) and the opening degree of the electric regulating valve (2). When the liquid level is higher than the initial set value and continues to rise, the liquid film is too thick. At this time, the circulating working fluid pump (1) pumps out the liquid working fluid accumulated at the bottom of the liquid film evaporator (4), and at the same time controls the flow rate by reducing the opening of the electric regulating valve (2) to control the liquid film thickness and maintain the ultra-high heat transfer coefficient under forced liquid film convection heat transfer. When the liquid level is lower than the initial set value and continues to decrease, the liquid film is too thin or even the wall is dry and there is no liquid film, which leads to the deterioration of the second type of heat transfer due to insufficient liquid content. At this time, the circulating working fluid pump (1) does not work and controls to increase the opening of the electric regulating valve (2) and increase the liquid working fluid flow to maintain a suitable liquid film thickness on the wall of the liquid film evaporator (4), ensuring that the evaporator wall is always in a forced liquid film convection heat transfer state and maintaining a high efficiency evaporation heat transfer coefficient. When the liquid level change is in dynamic equilibrium, the circulating working fluid pump (1) does not work and the electric regulating valve (2) keeps the current opening unchanged to maintain the current liquid working fluid flow constant, thereby ensuring that the liquid film thickness on the wall of the liquid film evaporator (4) is within a reasonable range. The upper inner wall of the liquid film evaporator (4) is provided with an annular groove (4-1), and there is a certain gap between the annular groove (4-1) and the outermost ring of the distributor (5). After the liquid working fluid jet enters the annular groove (4-1), it will flow down in a counterclockwise spiral along the inner wall of the groove. At the same time, a large number of slender inner wall groove channels (4-2) are seamlessly connected at the bottom of the annular groove (4-1) to increase the heat exchange area and facilitate the formation of liquid film heat exchange. The liquid separator (5) is in the form of a disc or a spiral tube; When the liquid working medium enters from the center, it flows out from the distributor (5) in a counterclockwise direction. The outermost ring of the distributor (5) is provided with multiple openings (5-1) along the flow direction of the liquid working medium. The number of openings can be adjusted according to the actual application requirements. The openings (5-1) are arranged tangentially, so that the liquid working medium is guided to flow out tangentially along the circumference through the openings (5-1). The spiral motion is sprayed into the annular groove (4-1) on the upper inner wall of the liquid film evaporator (4), ensuring that the liquid working medium can be evenly distributed into the inner wall groove channel (4-2) of the liquid film evaporator (4) under the dual action of centrifugal force and gravity of the circumferential motion.

2. The high-efficiency liquid film evaporator with throttling controllable as described in claim 1, characterized in that: The inner wall groove channel (4-2) can take many different forms. The shape of the inner wall groove channel (4-2) can be straight, curved or broken, and its number can be flexibly set according to actual needs.

3. The high-efficiency liquid film evaporator with throttling controllable as described in claim 2, characterized in that: The connection between the bottom of the annular groove (4-1) and the inner wall groove channel (4-2) is rounded.

4. The operating method of a high-efficiency liquid film evaporator with throttling control as described in any one of claims 1-3, characterized in that: During operation, the liquid working medium first enters the system through the electric regulating valve (2); inside the distributor (5), the spiral motion of the liquid working medium rotates counterclockwise, and finally exits tangentially through multiple openings (5-1) set on its outermost ring. The liquid working medium that is tangentially ejected will quickly and evenly splash into the annular groove (4-1) on the upper inner wall of the liquid film evaporator (4). After that, under the action of gravity, it flows down along the slender inner wall groove channel (4-2) inside the liquid film evaporator (4), forming a large number of independent liquid films with extremely high heat transfer coefficients on a large number of slender inner wall groove channels (4-2), which increases the heat transfer area and greatly improves the overall heat transfer coefficient of the evaporator. Meanwhile, a liquid level sensor (3) is set at the bottom of the liquid film evaporator (4) to monitor the liquid level height accumulated in the evaporator in real time. When the liquid level is too high, it indicates that the liquid film is too thick and the heat exchange efficiency is reduced. The signal is fed back to the circulating working fluid pump (1) to pump out the liquid working fluid accumulated at the bottom of the liquid film evaporator (4). At the same time, the opening of the electric regulating valve (2) is reduced to reduce the flow rate of the liquid working fluid, thereby matching the heat exchange load of the evaporator at this time, reducing the thickness of the liquid film, dynamically improving the heat exchange coefficient of the evaporator wall, and increasing the overall heat exchange efficiency. When the liquid level is too low, it indicates that the liquid film is too thin or even dries up, the heat exchange efficiency is reduced, the circulating working fluid pump (1) does not work, and the control system will increase the opening of the electric regulating valve (2) to increase the flow rate of the liquid working fluid, ensuring that a liquid film of appropriate thickness is formed on the inner wall of the liquid film evaporator (4), increasing the stability and continuity of the liquid film, and thus improving the overall heat exchange efficiency of the liquid film evaporator (4). When the liquid level is in dynamic equilibrium, the circulating working fluid pump (1) does not work and the electric regulating valve (2) maintains a stable opening to keep the liquid working fluid flow constant. In this way, the efficient, stable and controllable operation of the split liquid film evaporator is ensured, thereby achieving the ideal working state and effect.

5. The operating method of a high-efficiency liquid film evaporator with throttling control as described in claim 4, characterized in that: When the flow rate is high, multiple liquid-film evaporators need to be connected in parallel to form a parallel module of liquid-film evaporators with throttling control. Under the same floor space, multiple slender liquid-film evaporators can significantly increase the liquid film area compared to a single liquid-film evaporator, thereby greatly improving the heat exchange efficiency. When the flow rate is low, the demand can be met by operating only a single liquid-film evaporator.

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