Liquid level fluctuation preventing marine flooded evaporator

Abstract

The application relates to a marine full-liquid evaporator capable of preventing liquid surface shaking, and belongs to the technical field of water chilling units. The marine full-liquid evaporator capable of preventing liquid surface shaking comprises an evaporation tank, heat exchange pipes arranged in the evaporation tank and used for circulating refrigerants, a separation tank arranged between the evaporation tank and a compressor, and a horizontal communication flow channel arranged in communication between the upper portion of the evaporation tank and the bottom of the separation tank; a partition plate is arranged in the evaporation tank, a suction flow channel is arranged between the partition plate and the evaporation tank, and a plurality of groups of baffle plates are arranged below the partition plate in a spaced mode. The arc-shaped partition plate and the multistage up-and-down bent baffle plates arranged in the evaporation tank effectively intercept the liquid which is rolled up and beaten due to the shaking of a ship body, the baffle plates gradually consume the kinetic energy of the liquid, the liquid is centrally guided to the lower portion of the partition plate in cooperation with the design of the flow guide surface on the baffle blocks, the content of the liquid droplets splashed into the suction flow channel is greatly reduced, the liquid content of gas is reduced from the source, and the working load of the separation tank is reduced.

Description

Technical Field

[0001] This application relates to the field of chiller technology, and in particular to a marine-type evaporator designed to prevent liquid level sloshing. Background Technology

[0002] In modern ship cold chain transportation, ship air conditioning and refrigeration systems, flooded evaporators are widely used due to their advantages such as high heat transfer efficiency and low refrigerant charge. Existing flooded evaporators typically include an evaporator tank, heat exchange tubes installed inside the evaporator tank for refrigerant circulation, and a refrigerant circulation system driven by a compressor. The compressor extracts the refrigerant gas after it has absorbed heat and vaporized from the top of the evaporator tank, then circulates it to release heat and condense it into liquid refrigerant, which is then returned from the bottom of the evaporator tank to complete a continuous phase change heat transfer process.

[0003] However, during actual ship navigation, due to complex sea conditions, the hull will experience periodic rolling, pitching, and tilting. This special application environment poses a severe challenge to traditional flooded evaporators, mainly due to the following technical defects: The compressor and evaporator are usually directly connected or connected by a simple pipeline. When the ship shakes violently, the liquid refrigerant in the evaporator will fluctuate and roll violently under the action of inertial force, and even generate a large number of splashing droplets. This makes it very easy for the compressor to directly suck liquid refrigerant or a gas-liquid mixture with a large amount of liquid mist into the cylinder when it is pumping gas. Liquid refrigerant is incompressible. After entering the compressor, it will cause the "liquid slugging" phenomenon, which will cause serious chronic wear or even instantaneous damage to the internal parts of the compressor, greatly shortening the service life of the equipment. When the ship tilts and rocks, the refrigerant level in the evaporator tank will shift significantly. The liquid at the higher end will quickly flow out, initially rolled up by inertial force and flowing to one side, exposing a large area of ​​the heat exchange tubes on the rolled-up side to the air. After flowing, some liquid falls back, reducing the exposed area. During this process, the heat exchange area decreases. In addition, due to the tilted state, the exposed area cannot be completely covered. Since the heat transfer coefficient of gas is much lower than that of liquid, the exposed heat exchange tubes almost lose their heat exchange capacity, resulting in a reduction in the overall effective heat exchange area of ​​the evaporator and a drop in refrigeration efficiency. Although the liquid level will recover when the ship tilts in the opposite direction, the stability and energy efficiency ratio of the refrigeration system have been severely affected during the interval between each tilt. Summary of the Invention

[0004] Therefore, it is necessary to provide a marine-type evaporator that prevents liquid level sloshing in order to address the above-mentioned technical problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A marine-grade flooded evaporator designed to prevent liquid level sloshing includes an evaporator tank, heat exchange tubes installed inside the evaporator tank for refrigerant circulation, a separator tank between the evaporator tank and a compressor, and a transverse connecting channel between the upper part of the evaporator tank and the bottom of the separator tank. The evaporator tank contains a baffle plate, and a suction channel is provided between the baffle plate and the evaporator tank. Multiple sets of baffles are also installed at intervals below the baffle plate.

[0006] Preferably, the transverse connecting channel is configured as at least two separate columnar connecting pipes.

[0007] Preferably, both ends of the baffle are equipped with baffle blocks, which are installed on the inner wall of the evaporator.

[0008] Furthermore, both sides of the baffle are provided with guide surfaces, and the guide surfaces are inclined to one side of the baffle.

[0009] Furthermore, the partition is arranged in an arc shape.

[0010] Furthermore, when the evaporator tilts and shakes, a flow-blocking cavity is formed between the baffle and the partition.

[0011] Furthermore, the baffle is configured to be bent vertically.

[0012] Preferably, the evaporator is provided with buffer tanks at both ends, the lower end of the buffer tank is provided with an opening, the connecting exhaust port is located at the upper end of the partition and communicates with the suction channel, and the opening is located at the upper end of the liquid refrigerant surface.

[0013] Furthermore, a rotating blade is rotatably provided at the bottom of the buffer box, the through-hole is provided on the rotating blade, and a limiting protrusion is provided on the buffer box.

[0014] Furthermore, the upper end of the buffer box is provided with a connecting vent.

[0015] Compared with the prior art, the present invention provides a marine flooded evaporator that prevents liquid level sloshing, which has the following beneficial effects: This invention adds a separator between the evaporator and the compressor, along with at least two columnar connecting pipes located at both ends of the evaporator. On the one hand, the double connecting pipe design ensures that at least one pipe opening is blocked by liquid when the evaporator is tilted, forcing the gas to change course. On the other hand, after the gas-liquid mixture enters the separator, it utilizes the sudden expansion of cross-sectional area and the abrupt change in flow direction to achieve efficient centrifugal separation by relying on the inertial difference between the gas and liquid phases. The droplets coalesce and settle, allowing the gas to be deeply dried. This invention effectively intercepts liquid that is rolled up and slapped by the swaying of the ship by setting arc-shaped baffles and multi-stage up-and-down bending baffles inside the evaporator. The baffles consume the kinetic energy of the liquid in stages. With the design of the guide surface on the baffle, the liquid is concentrated and guided to the bottom of the baffle, which greatly reduces the amount of liquid droplets splashing into the suction channel, reduces the liquid content of the gas from the source, and reduces the workload of the separator. When the hull sways and causes the liquid surface to tilt, the buffer tank at the lower position can quickly store liquid; and when the swaying reverses and the liquid rises to the higher position, the gravity of the liquid drives the rotating blades to automatically change the opening, so as to achieve slow and continuous dripping of liquid. This invention solves the problem of exposed heat exchange tubes at the higher position, so that they can still participate in heat exchange during the swaying interval, ensuring the stability and continuity of the evaporator heat exchange efficiency throughout the entire swaying cycle. Attached Figure Description

[0016] Figure 1 This is a front view of the existing technology; Figure 2 A top view of the prior art; Figure 3 A side view of the prior art; Figure 4 This is the front view of the present invention; Figure 5 This is a top view of the present invention; Figure 6 This is a side view of the present invention; Figure 7 This is a schematic diagram of the partition structure in this invention; Figure 8 This is a frontal cross-sectional view of the present invention; Figure 9 For the present invention Figure 8 An enlarged schematic diagram of part A in the middle; Figure 10 This is a side cross-sectional view of the present invention; Figure 11 This is a schematic diagram of the baffle structure in this invention; Figure 12 This is a schematic diagram of the buffer box structure in this invention; Figure 13 This is a schematic diagram of the rotating blade in this invention.

[0017] In the diagram: 1. Evaporator; 101. Heat exchange tube; 2. Separator; 201. Connecting pipe; 3. Baffle; 301. Baffle; 302. Baffle block; 303. Guide surface; 4. Buffer tank; 401. Rotating blade; 402. Limiting protrusion; 403. Through port; 404. Connecting exhaust port. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] Example: A marine flooded evaporator designed to prevent liquid level sloshing, with reference to existing flooded evaporators. Figure 1 , Figure 2 , Figure 3 The system includes an evaporator 1 and a heat exchange tube 101 installed inside the evaporator 1 for refrigerant circulation. A refrigerant cavity circulates between the evaporator 1 and the heat exchange tube 101, through which the refrigerant is drawn and circulated by the compressor. The compressor draws the refrigerant gas, which has absorbed heat and vaporized, from the top of the evaporator 1. After circulating and releasing heat, the gas condenses into liquid refrigerant and then flows back into the evaporator 1 from the bottom. However, because the compressor and the evaporator are directly connected in the prior art, the drawn gas will contain some liquid mist. After the liquid mist enters the compressor, it will cause chronic wear inside the compressor. Especially when used on a ship, the evaporator 1 will shake with the swaying of the ship, causing the liquid refrigerant to be directly drawn into the compressor, accelerating the damage to the compressor. Reference Figure 4 , Figure 5 , Figure 6 Therefore, the present invention provides a separator tank 2 between the evaporator tank 1 and the compressor, and provides a transverse connecting channel between the upper part of the evaporator tank 1 and the bottom of the separator tank 2 to extend the path of the compressor when it draws gas, preventing the gas-liquid mixture from directly entering the compressor. When the gas-liquid refrigerant enters the separator tank 2 through the connecting channel, the flow cross-sectional area suddenly expands and the airflow direction changes abruptly. The gas and liquid phases separate due to the difference in inertia. The low-density gas has a small mass and low inertia, so it will quickly diffuse and change its flow direction to move upward. The high-density liquid droplets have a large mass and high inertia, so they are difficult to follow the airflow and turn synchronously. The droplets collide with each other and merge into larger droplets, and then settle under the action of gravity. This is similar to the liquefaction principle when flowing from high pressure to low pressure. At the same time, when the droplets collide with the inner wall of the separator tank 2, they will adhere to form a liquid film and fall along the wall, further separating the fine droplets.

[0020] In one specific implementation, refer to Figure 5 To ensure the stability of the vertical connection between the separator 2 and the evaporator 1, the transverse connecting channel is set as at least two separate columnar connecting pipes 201, with two of the connecting pipes 201 located at the two ends of the evaporator 1 respectively. When the ship hull is rocking, at least one connecting pipe 201 can be blocked by the refrigerant liquid, which facilitates the upward movement of the gas-liquid mixture.

[0021] In one specific embodiment, the liquid mist accompanying the extracted gas is also partly caused by the hull's rolling motion. When the hull rolls, the liquid, under the action of inertial force, rolls up from one side and slaps to the other side, causing liquid droplets to splash everywhere. As the gas rises, it carries some of these droplets, resulting in the extraction of a gas-liquid mixture. Therefore, referring to... Figure 7 , Figure 10 A baffle 3 is installed inside the evaporator 1. The baffle 3 is located at the lower end of the connecting pipe 201 and above the refrigerant liquid surface. A suction flow channel is provided between the baffle 3 and the evaporator 1. At the same time, multiple sets of baffles 301 are installed at intervals below the baffle 3. The baffles 301 are located above the refrigerant liquid surface. When the hull shakes and the liquid rolls up, the liquid is intercepted by the multiple sets of baffles 301 step by step. When the liquid hits the baffle, it is intercepted and flows down step by step, reducing the kinetic energy and instantaneous flow rate of the liquid when it enters the next baffle. This reduces the force of hitting the liquid surface, reduces the splashing of liquid droplets, and reduces the content of liquid droplets in the gas.

[0022] In one specific embodiment, to facilitate the installation and fixing of the partition 3 and the baffle 301, refer to Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 11 A baffle 302 is installed at both ends of the baffle 301, and the baffle 302 is installed on the inner wall of the evaporator 1.

[0023] Since the baffle 302 is located on both sides of the baffle 301 at the suction channel, when the rolled-up liquid hits the baffle 302, it will enter the suction channel, increasing the liquid content in the gas-liquid mixture. Therefore, refer to... Figure 11 A flow guiding surface 303 is provided on both sides of the baffle 302. The flow guiding surface 303 is inclined to one side of the baffle 301. When the liquid refrigerant comes into contact with the baffle 302, it will be guided to the baffle 301 by the influence of the flow guiding surface 303, so that the liquid is concentrated below the baffle 3 instead of on both sides, thereby reducing the upward movement of the liquid refrigerant with the gas.

[0024] In one specific implementation, refer to Figure 7 , Figure 10The baffle 3 is arc-shaped, which makes the thickness of the suction channel between the baffle 3 and the inner wall of the evaporator 1 equal, resulting in more uniform suction. At the same time, the space at the lower middle part of the baffle 3 is larger than the space at the lower sides, providing a buffer for the liquid refrigerant to flow to the middle and increasing the flow rate of the intercepted liquid, reducing the impact force of the subsequent swirling liquid surface. Meanwhile, when the liquid refrigerant hits the baffle 3, the splashed droplets will be enveloped by the subsequent impact gas, and the unencapsulated droplets will be guided back to the refrigerant liquid surface along the lower arc surface of the baffle 3 and the guide surface 303 of the baffle 302.

[0025] In one specific embodiment, when the evaporator 1 sways with the hull, the liquid refrigerant in the tilted evaporator 1 increases at the lower part and decreases at the higher part, resulting in the heat exchange tubes 101 being exposed at the higher part. Although the swaying intervals are short and liquid is replenished during the next reverse sway, the exposed heat exchange tubes 101 significantly reduce the heat exchange area of ​​the refrigerant during a single sway, thus reducing the heat exchange effect. Therefore, referring to... Figure 8 When the evaporator 1 shakes and tilts, the intercepting cavity formed between the baffle 3 and the baffle 301 gradually drips down after the rolled-up liquid flows through, replenishing the exposed heat exchange tube 101. This allows the rolled-up liquid to still participate in the heat exchange work after being intercepted, and it can quickly flow into the overall liquid surface after heat exchange, ensuring the heat exchange effect.

[0026] In one specific embodiment, the rolled-up liquid has a certain impact force when it impacts the baffle 301. When used on a small boat hull, the evaporator 1 has a small volume and the refrigerant impact force is limited. (Refer to...) Figure 11 The baffle 301 is designed to be bent vertically, which increases the contact area during impact and can better resist the impact force of liquid on the baffle 301. At the same time, when the baffle 301 is bent, the amount of liquid intercepted is increased, which improves the continuity of heat exchange when the liquid drips. When used in large-volume ship hulls, when the evaporator 1 is large, due to the large internal refrigerant flow, the baffle 301 is prone to bending and damage when it is bent. Therefore, the baffle 301 is designed to be flat.

[0027] In one specific embodiment, during the shaking process, the heat exchange tube 101 located at the end of the evaporator 1 has a larger exposed area, and the rolled-up liquid surface starts from the end. Therefore, the heat exchange tube 101 at the end is more easily exposed, and without refrigerant liquid replenishment, the heat exchange effect is most significantly reduced. Therefore, referring to... Figure 8 , Figure 9 , Figure 12Buffer tanks 4 are provided at both ends of the evaporator 1. The lower end of the buffer tank 4 is provided with an opening 403 and the upper end is provided with a connecting exhaust port 404. The connecting exhaust port 404 is located at the upper end of the partition 3 and is connected to the suction channel. The opening 403 is located at the upper end of the liquid refrigerant surface. When the evaporator 1 is rocked with the hull, the liquid refrigerant at the lower part will enter the buffer tank 4 through the opening 403 for temporary storage. The air in the cavity of the buffer tank 4 is discharged from the connecting exhaust port 404. When the evaporator 1 is rocked in the opposite direction, the buffer tank 4 containing the liquid refrigerant is located at the top. At this time, when the liquid refrigerant is rolled up and flows downward, the liquid refrigerant in the buffer tank 4 gradually flows out from the opening 403 and replenishes the exposed heat exchange tube 101 below, ensuring heat exchange efficiency.

[0028] In one specific embodiment, since the frequency of the ship's swaying is short, in order to facilitate better entry of liquid refrigerant into the buffer tank 4, refer to... Figure 9 , Figure 13 The bottom of the buffer tank 4 is rotatably equipped with a rotating blade 401, and an opening 403 is provided on the rotating blade 401. A limiting protrusion 402 is provided on the buffer tank 4 to prevent the rotating blade 401 from sticking to the inner wall of the buffer tank 4 after rotation. When the buffer tank 4 is at a low position, the liquid refrigerant entering the buffer tank 4 will push the rotating blade 401 to rotate until it is in contact with the limiting protrusion 402, increasing the area of ​​the opening 403 and increasing the liquid replenishment speed. When the buffer tank 4 is at a high position, the liquid refrigerant will flow out from the buffer tank 4, pushing the rotating blade 401 to move down and reducing the area of ​​the opening 403, so that the liquid refrigerant can flow out continuously and slowly, continuously replenishing the exposed heat exchange tube 101 in a single oscillation cycle, ensuring heat exchange efficiency.

[0029] In a specific workflow, after the system starts, the liquid refrigerant enters the bottom of the evaporator 1 after being throttled and depressurized by the expansion valve, immersing the heat exchange tube 101. The refrigerant in the heat exchange tube 101 exchanges heat with the liquid refrigerant, and the liquid refrigerant absorbs heat and vaporizes. At the same time, the compressor runs, drawing the vaporized refrigerant gas from the top of the evaporator 1, and transporting it through pipelines to the condenser to release heat and condense. The refrigerant, after being reliquefied, flows back from the bottom of the evaporator 1, thus forming a closed refrigeration cycle. When the ship is stable, the refrigerant gas with a small amount of liquid mist mixed in the upper part of the evaporator 1 enters the separator 2 through at least two columnar connecting pipes 201 set at both ends of the evaporator 1. By setting the connection path to at least two independent connecting pipes 201, it can be ensured that the inlet of at least one connecting pipe 201 is blocked by liquid refrigerant when the ship is rocking or the evaporator 1 is tilted, forcing the gas to rise through the other connecting pipes 201 instead, thus avoiding a large amount of liquid directly rushing into the compressor.

[0030] As the ship sways, the evaporator 1 tilts accordingly. Under the influence of inertial force, the liquid refrigerant is swept up and slapped from the lower to the upper level. The swept-up liquid refrigerant first impacts multiple sets of vertically bent baffles 301 fixed to the inner wall of the evaporator 1. The baffles 301 intercept the liquid step by step, reducing its kinetic energy and decreasing the impact force on the liquid surface below, thereby reducing the amount of droplet splashing. The liquid that impacts the baffle 302 is guided by the inclined guide surfaces 303 on both sides and is concentrated and directed to the baffle 301 instead of being scattered into the suction channels on both sides, further reducing the liquid content of the gas. The liquid intercepted by the baffle 301 flows down the plate surface and gathers below the arc-shaped baffle 3. The arc design of the baffle 3 makes the suction channel uniform in thickness and the central space large, providing buffering and collection space for the liquid.

[0031] The relatively clean gas, after primary interception, enters the separator 2 through the suction channel between the baffle 3 and the inner wall of the evaporator 1, and then through the connecting pipe 201. Due to the sudden expansion of the flow cross-sectional area inside the separator 2 compared to the connecting pipe 201 and the abrupt change in the airflow direction, the gas and liquid phases separate due to inertia: the low-density gas has a small mass and low inertia, so it diffuses rapidly and changes direction to move upward; the high-density droplets have a large mass and high inertia, so they are difficult to follow the airflow and turn synchronously. The droplets collide with each other and merge into larger droplets, which then settle under the action of gravity. Some of the fine droplets adhere to the inner wall of the separator 2 when they collide, forming a liquid film, and slide down the wall surface. As a result, the gas entering the compressor is fully dried, and liquid slugging is completely avoided.

[0032] During the tilting process, the buffer tank 4 located at the lower position is submerged more deeply relative to the liquid surface. Liquid refrigerant flows into the tank through the opening 403 at the bottom of the buffer tank 4 for temporary storage. The gas inside the tank is discharged from the exhaust port 404 at the top. The inflowing liquid pushes the rotating blade 401 to rotate until it hits the limiting protrusion 402. At this time, the opening 403 has the largest area, which accelerates the liquid storage speed, and the liquid refrigerant is temporarily stored in the buffer tank 4.

[0033] When the ship rolls in the opposite direction, the buffer tank 4, which was originally at a high position, moves to a lower position. The liquid refrigerant temporarily stored in the tank begins to flow out through the port 403. The flowing liquid pushes the rotating blade 401 downward, partially blocking the port 403 and reducing the area of ​​the port 403. The liquid refrigerant then drips continuously and slowly, precisely replenishing the surface of the heat exchange tube 101 exposed due to the drop in liquid level. At the same time, the liquid intercepted by the baffle 301 and the partition 3 also drips down gradually, covering the exposed heat exchange tube 101.

[0034] During the intervals between individual swaying events, the heat exchange tube 101 remains moist and continues to exchange heat, ensuring that the overall heat exchange efficiency of the evaporator 1 is not affected by the swaying of the ship. Throughout the entire voyage, this effectively protects the compressor from liquid slugging damage and maintains the evaporator's efficient and stable heat exchange.

Claims

1. A marine-grade flooded evaporator for preventing liquid level sloshing, comprising an evaporator tank (1) and heat exchange tubes (101) installed inside the evaporator tank (1) for refrigerant circulation, characterized in that, A separator (2) is provided between the evaporator (1) and the compressor, and a transverse connecting channel is provided between the upper part of the evaporator (1) and the bottom of the separator (2); The evaporator (1) is provided with a baffle (3), and a suction channel is provided between the baffle (3) and the evaporator (1). At the same time, multiple sets of baffles (301) are installed at intervals below the baffle (3).

2. The marine-grade flooded evaporator for preventing liquid level sloshing as described in claim 1, characterized in that, The transverse connecting channels are configured as at least two separate columnar connecting pipes (201).

3. The marine-grade flooded evaporator for preventing liquid level sloshing as described in claim 1, characterized in that, Both ends of the baffle (301) are equipped with baffles (302), which are installed on the inner wall of the evaporator (1).

4. The marine-grade flooded evaporator for preventing liquid level sloshing according to claim 3, characterized in that, Both sides of the baffle (302) are provided with guide surfaces (303), and the guide surfaces (303) are inclined to one side of the baffle (301).

5. The marine-grade flooded evaporator for preventing liquid level sloshing according to claim 4, characterized in that, The partition (3) is arranged in an arc shape.

6. The marine-grade flooded evaporator for preventing liquid level sloshing according to claim 4, characterized in that, When the evaporator (1) shakes and tilts, a flow-blocking cavity is formed between the partition (3) and the baffle (301).

7. The marine flooded evaporator for preventing liquid level sloshing according to claim 3, characterized in that, The baffle (301) is configured to be bent vertically.

8. The marine flooded evaporator for preventing liquid level sloshing according to claim 3 or 7, characterized in that, Both ends of the evaporator (1) are provided with buffer tanks (4), and the lower end of the buffer tank (4) is provided with a port (403), which is located at the upper end of the liquid refrigerant surface.

9. The marine flooded evaporator for preventing liquid level sloshing according to claim 8, characterized in that, The bottom of the buffer box (4) is rotatably provided with a rotating blade (401), the opening (403) is provided on the rotating blade (401), and the buffer box (4) is provided with a limiting protrusion (402).

10. The marine-grade flooded evaporator for preventing liquid level sloshing according to claim 8, characterized in that, The upper end of the buffer box (4) is provided with a connecting exhaust port (404), which is located at the upper end of the partition (3) and connected to the suction channel.

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