Liquid distributor, falling film evaporator and chiller

Abstract

The present invention relates to a liquid distributor, a falling film evaporator and a chiller, comprising: a first flow guide member having a first flow guide cavity therein, a first outlet connected to the first flow guide cavity being provided on the first flow guide member, and the first outlet being located below the first flow guide cavity in the direction of gravity; a liquid distributor, comprising a liquid distributor section, the liquid distributor section being arranged in the first flow guide cavity around a first axis, the first axis extending in the direction of gravity, a liquid distributor cavity being provided in the liquid distributor section, a first inlet and a second outlet both connected to the liquid distributor cavity being provided at both ends of the liquid distributor section; at least two liquid distributor holes connected to the liquid distributor cavity being provided on the surface of the cavity wall of the first flow guide cavity facing the liquid distributor section; all the liquid distributor holes are spaced apart from each other in the extension direction of the liquid distributor section, and can spray the liquid flowing out of the liquid distributor cavity to the cavity wall of the first flow guide cavity. The liquid distributor can separate the gas-liquid two-phase refrigerant, and distribute the liquid refrigerant separately, thereby ensuring the uniformity of the liquid distribution, and thus ensuring the heat exchange performance of the falling film evaporator.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange, and in particular to a liquid distributor, a falling film evaporator and a chiller. Background Art

[0002] Evaporators include dry evaporators, flooded evaporators and falling film evaporators. Among them, falling film evaporators are widely used by refrigeration equipment manufacturers due to their high heat exchange efficiency and low refrigerant consumption.

[0003] Generally, a falling film evaporator includes a liquid distributor and a heat exchange tube. After the refrigerant is evenly distributed in the liquid distributor, it drips from top to bottom on the outer surface of the heat exchange tube. The refrigerant flows axially and circumferentially on the outer surface of the heat exchange tube to form a layer of liquid film. The liquid film absorbs the heat of the hot fluid in the tube through the tube wall of the heat exchange tube to evaporate, thereby reducing the temperature of the hot fluid in the heat exchange tube and then discharging it.

[0004] In order to ensure the heat exchange performance of the falling film evaporator, it is necessary to ensure the uniformity of the film of the refrigerant on the outer surface of the heat exchange tube, and the liquid distributor is the key to ensure the uniformity of the film on the outer surface of the heat exchange tube. However, the liquid distributor of the traditional falling film evaporator has poor liquid distribution uniformity, which leads to poor uniformity of the refrigerant film on the outer surface of the heat exchange tube, thus affecting the heat exchange performance of the falling film evaporator. Summary of the invention

[0005] Based on this, it is necessary to provide a liquid distributor, a falling film evaporator and a chiller that can improve the liquid distribution uniformity in order to address the problem of poor liquid distribution uniformity of the liquid distributor of a traditional falling film evaporator.

[0006] A liquid distributor, comprising:

[0007] A first flow guide member of a first flow guide cavity is provided therein, and a first outlet communicating with the first flow guide cavity is provided on the first flow guide member. In the direction of gravity, the first outlet is located below the first flow guide cavity;

[0008] A liquid distributing member, comprising a liquid distributing section, the liquid distributing section is arranged in a first flow guiding cavity around a first axis, the first axis extends in the gravity direction, a liquid distributing cavity is arranged in the liquid distributing section, and a first inlet and a second outlet are respectively opened at two ends of the liquid distributing section, both of which are connected to the liquid distributing cavity;

[0009] Among them, at least two liquid distribution holes connected to the liquid distribution cavity are provided on the surface of the cavity wall of the liquid distribution section facing the first flow guide cavity; all the liquid distribution holes are spaced apart from each other in the extension direction of the liquid distribution section, and can spray the liquid flowing out of the liquid distribution cavity toward the cavity wall of the first flow guide cavity.

[0010] In one embodiment, the liquid distributing section extends spirally around the first axis.

[0011] In one embodiment, the liquid distribution section is provided at least once around the first axis, and all the liquid distribution holes are provided at least once around the first axis.

[0012] In one of the embodiments, in the gravity direction, the position of the first inlet is lower than the position of the second outlet.

[0013] In one embodiment, the liquid distribution holes are evenly spaced apart on the liquid distribution section, and the diameters of the liquid distribution holes gradually increase from one end of the liquid distribution section close to the first inlet to one end close to the second outlet.

[0014] In one embodiment, all the liquid distribution holes have the same aperture, and the distance between two adjacent liquid distribution holes gradually decreases from an end of the liquid distribution section close to the first inlet to an end close to the second outlet.

[0015] In one embodiment, the first axis forms a first central axis of the liquid distribution section, and the first central axis overlaps with a second central axis of the first flow guiding cavity.

[0016] In one embodiment, the liquid distributing member further comprises a first liquid inlet section, and the first liquid inlet section is connected to an end of the liquid distributing section provided with the first inlet;

[0017] The first inlet has a third central axis, and the first liquid inlet section extends along the third central axis.

[0018] In one embodiment, the liquid distributor further includes drainage needles, and all of the drainage needles are arranged at intervals from each other on the end surface of the first flow guide member where the first outlet is provided.

[0019] In one embodiment, the distance between every two adjacent drainage needles is equal, and the lengths of all the drainage needles are the same.

[0020] In one embodiment, the length of each drainage needle ranges from 10 mm to 50 mm.

[0021] A falling film evaporator, comprising:

[0022] A shell assembly, wherein an assembly cavity is provided in the shell assembly, and a third outlet communicating with the assembly cavity is also provided on the shell assembly;

[0023] a heat exchange tube, at least a portion of which is disposed in the assembly cavity;

[0024] The liquid distributor as described in any one of the above items, wherein the first flow guide is arranged in the assembly cavity, and in the gravity direction, the first flow guide is located above the heat exchange tube;

[0025] Wherein, at least a portion of the heat exchange tube is located on the flow path of the refrigerant flowing out of the first outlet, and the second outlet and at least a portion of the outer surface of the heat exchange tube are both connected to the third outlet.

[0026] In one embodiment, the heat exchange tube comprises a second liquid inlet section, a coil and a first liquid outlet section connected in sequence, the coil extends spirally in the gravity direction, and the second liquid inlet section and the first liquid outlet section are arranged on the shell assembly;

[0027] The coil is located on a flow path where the refrigerant flows out of the first outlet, and an outer surface of the coil is connected to the third outlet.

[0028] In one embodiment, the falling film evaporator also includes a second flow guide member arranged inside the first flow guide member, and the liquid distribution section is arranged outside the second flow guide member; a second flow guide cavity is arranged inside the second flow guide member, and a second inlet and a fourth outlet are provided on the second flow guide member, both of which are connected to the second flow guide cavity, the second outlet and at least part of the outer surface of the heat exchange tube are connected to the second inlet, and the fourth outlet is connected to the third outlet.

[0029] In one embodiment, one end of the first flow guide member away from the first outlet is connected to the cavity wall of the assembly cavity;

[0030] Among them, the liquid distribution part also includes an air outlet section, which is connected to one end of the liquid distribution section where the second outlet is provided. The air outlet section is located in the first guide cavity, and the air outlet section is provided with an air outlet hole on the outer surface of the cavity wall of the assembly cavity facing the first outlet.

[0031] A chiller comprises the falling film evaporator as described in any one of the above items.

[0032] In the above-mentioned liquid distributor, falling film evaporator and chiller, when the gas-liquid two-phase refrigerant flows from the first inlet to the liquid distribution cavity, since the liquid distribution section is arranged around a first axis extending in the gravity direction, the gas-liquid two-phase refrigerant will be subjected to centrifugal force when flowing at high speed in the liquid distribution cavity. Since the gaseous refrigerant and the liquid refrigerant have different densities, the centrifugal forces they are subjected to during the flow in the liquid distribution cavity are also different. The liquid refrigerant with a larger density flows toward the outside of the liquid distribution section relative to the gaseous refrigerant with a smaller density, and finally sprays from the liquid distribution hole onto the cavity wall of the first flow guide cavity, and flows to the external heat exchange tube for heat exchange and evaporation. In this way, the liquid distributor can separate the gas-liquid two-phase refrigerant and distribute the liquid refrigerant alone. Compared with the gas-liquid two-phase liquid distribution in the prior art, the interference of the gaseous refrigerant on the liquid distribution is reduced, the uniformity of the liquid distribution is ensured, and thus the heat exchange performance of the falling film evaporator is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A structural diagram of a falling film evaporator provided in one embodiment of the present invention;

[0034] Figure 2 for Figure 1 A partial structural diagram of a liquid distributor of a falling film evaporator shown in FIG.

[0035] Figure 3 for Figure 2 A structural diagram of a liquid distributing member of a liquid distributing device from one perspective shown in ;

[0036] Figure 4 for Figure 3 A structural diagram of the liquid dispensing member from another perspective shown in ;

[0037] Figure 5 for Figure 2 The structural diagram of the first flow guide member and the drainage needle of the liquid distributor shown in ;

[0038] Figure 6 for Figure 5 A plan view of the structure shown in ;

[0039] Figure 7 for Figure 3 A structural diagram of the liquid dispensing member from another perspective shown in ;

[0040] Figure 8 for Figure 2 The structural diagram of the liquid distributor is shown in .

[0041] 100. Falling film evaporator; 10. Shell assembly; 11. Assembly chamber; 12. Third outlet; 13. Shell; 14. Air outlet pipe; 15. Cover plate; 20. Liquid distributor; 21. First flow guide; 211. First flow guide chamber; 212. First outlet; 22. Liquid distributor; 221. Liquid distribution section; 2211. Liquid distribution hole; 222. First liquid inlet section; 223. Air outlet section; 2231. Air outlet hole; 23. Drainage needle; 30. Heat exchange tube; 31. Second liquid inlet section; 32. Coil; 33. First liquid outlet section; 40. Second flow guide; 41. Second inlet. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0047] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0048] As described in the background technology, the liquid distribution uniformity of the liquid distributor of the traditional falling film evaporator is poor, which leads to poor uniformity of the refrigerant film on the outer surface of the heat exchange tube, thereby affecting the heat exchange performance of the falling film evaporator.

[0049] The inventors of the present application have found that the reason for the above-mentioned problems is that in a traditional falling film evaporator, the supercooled liquid refrigerant flowing out of the condenser is converted into a gas-liquid two-phase refrigerant after being cooled and reduced in pressure by a throttling device. The gas-liquid two-phase refrigerant flows to the liquid distributor of the falling film evaporator for liquid distribution, that is, the traditional falling film evaporator distributes liquid to both the gas and liquid phases. During the liquid distribution, the gas phase interferes with the liquid phase, resulting in poor liquid distribution uniformity, which in turn affects the heat exchange performance of the falling film evaporator.

[0050] See also Figure 1 An embodiment of the present invention provides a falling film evaporator 100 for a chiller. Specifically, the chiller may be a modular chiller or a household chiller.

[0051] The falling film evaporator 100 includes a shell assembly 10, a liquid distributor 20 and a heat exchange tube 30. An assembly cavity 11 is provided in the shell assembly 10. A third outlet 12 communicating with the assembly cavity 11 is provided on the shell assembly 10. At least part of the liquid distributor 20 and the heat exchange tube 30 are arranged in the assembly cavity 11. In the gravity direction, the liquid distributor 20 is located above the heat exchange tube 30. After being evenly distributed in the liquid distributor 20, the refrigerant drips from top to bottom on the surface of the heat exchange tube 30. The refrigerant flows along the length direction and circumferential direction of the outer surface of the heat exchange tube 30 to form a layer of liquid film. The liquid film absorbs the heat of the liquid in the tube through the tube wall of the heat exchange tube 30 to evaporate and is discharged from the third outlet 12, thereby reducing the temperature of the hot fluid in the heat exchange tube 30 and then flowing out.

[0052] The housing assembly 10 includes a housing 13, an air outlet pipe 14 and a cover plate 15, wherein the cover plate 15 is covered on the housing 13, the air outlet pipe 14 and the cover plate 15 are connected, the housing 13 and the cover plate 15 define an assembly cavity 11, and the third outlet 12 is provided on the air outlet pipe 14. It should be understood that in other embodiments, the housing assembly 10 may also omit the air outlet pipe 14, and the third outlet 12 may be directly provided on the cover plate 15.

[0053] In one embodiment, the liquid distributor 20 includes a first flow guide 21 and a liquid distributor 22. The first flow guide 21 is disposed in the assembly chamber 11. A first flow guide chamber 211 is disposed in the first flow guide 21. A first outlet 212 communicating with the first flow guide chamber 211 is disposed on the first flow guide 21. In the gravity direction, the first outlet 212 is located below the first flow guide chamber 211. The portion of the heat exchange tube 30 disposed in the assembly chamber 11 is located on the flow path where the refrigerant flows out of the first outlet 212. The liquid distributor 22 includes a liquid distributor section 221 (see Figure 2-Figure 4 ), the liquid distribution section 221 is disposed around the first axis in the first flow guiding cavity 211 (see Figure 1 ) in the liquid distribution section 221, the first axis extends in the direction of gravity; a liquid distribution cavity is provided in the liquid distribution section 221, and a first inlet connected to the liquid distribution cavity and a second outlet connected to the third outlet 12 are respectively provided at both ends of the liquid distribution section 221. Liquid distribution holes 2211 connected to the liquid distribution cavity are provided on the surface of the cavity wall of the liquid distribution section 221 facing the first flow guiding cavity 211, and the liquid distribution holes 2211 include at least two liquid distribution holes 2211, all of which are spaced apart from each other in the extension direction of the liquid distribution section 221, and each liquid distribution hole 2211 is configured to spray the liquid flowing out of the liquid distribution cavity onto the cavity wall of the first flow guiding cavity 211.

[0054] When the gas-liquid two-phase refrigerant flows from the first inlet to the liquid distribution cavity, since the liquid distribution section 221 is arranged around the first axis, the gas-liquid two-phase refrigerant will be affected by centrifugal force when flowing at high speed in the liquid distribution cavity. The gaseous refrigerant and the liquid refrigerant have different densities, and the centrifugal forces they are subjected to during the flow in the liquid distribution cavity are also different. The liquid refrigerant with greater density flows toward the outside of the liquid distribution section 221 relative to the gaseous refrigerant with less density, and finally sprays from the liquid distribution hole 2211 onto the wall of the first guide cavity 211, and the gaseous refrigerant with less density finally flows from the second outlet to the third outlet 12 for discharge. The liquid refrigerant sprayed onto the wall of the first guide cavity 211 flows from the first outlet 212 to the surface of the heat exchange tube 30 under the action of gravity and expands in the axial and circumferential directions to form a liquid film layer covering the surface of the heat exchange tube 30. The saturated refrigerant in the liquid film absorbs the heat of the hot fluid in the heat exchange tube 30, evaporates in the liquid film layer on the surface of the heat exchange tube 30 to generate gas, and the excess liquid refrigerant that does not participate in the evaporation drips downward layer by layer to participate in the heat exchange to generate gas. The generated gas and the gas discharged from the second outlet flow together to the third outlet 12 for discharge.

[0055] Through the above-mentioned arrangement, the liquid distributor 20 can separate the gas-liquid two-phase refrigerant and distribute the liquid refrigerant alone. Compared with the gas-liquid two-phase liquid distribution in the prior art, the interference of the gaseous refrigerant on the liquid distribution is reduced, the uniformity of the liquid distribution is ensured, and thus the heat exchange performance of the falling film evaporator 100 is ensured.

[0056] It should be noted that the thermal fluid flowing in the heat exchange tube 30 may be water or other liquids, such as ethylene glycol, and the type of the thermal fluid flowing in the heat exchange tube 30 is not limited.

[0057] See also Figure 5 and Figure 6 In one embodiment, the first flow guide 21 is a cylindrical structure, one end of the first flow guide 21 abuts against the cavity wall of the assembly cavity 11 to be closed, and the other end forms a first outlet 212 (see Figure 1 ), the first flow guide cavity 211 is connected to the third outlet 12, so that the cross-sectional shape of the first flow guide cavity 211 is circular, which facilitates the liquid refrigerant to flow down along the cavity wall of the first flow guide cavity 211 under the action of gravity. It should be understood that in other embodiments, the shape of the first flow guide 21 is not limited.

[0058] Specifically, the first axis forms the first central axis of the liquid distribution section 221, and the first central axis of the liquid distribution section 221 overlaps with the second central axis of the first flow guide cavity 211, so that the distance between each liquid distribution hole 2211 and the cavity wall of the first flow guide cavity 211 is equal, thereby increasing the uniformity of liquid distribution.

[0059] In one embodiment, the liquid distribution section 221 extends spirally around the first axis, so that there is a height difference between the first inlet and the second outlet, and the liquid refrigerant tends to flow downward relative to the gaseous refrigerant, and under the combined action of centrifugal force, the liquid refrigerant flows inward and downward, and the gas pressure refrigerant flows inward and upward, thereby ensuring that the interface between the gaseous refrigerant and the liquid refrigerant is more stable, and further ensuring the uniformity of the liquid output. Of course, in other embodiments, the positions of the liquid distribution section 221 at various locations in the direction of gravity can also be set to be flush, which is not limited here.

[0060] See also Figure 4 and Figure 7 The liquid distribution section 221 is provided with at least one circle around the first axis, and all the liquid distribution holes 2211 are provided with at least one circle around the first axis, so as to ensure that the liquid refrigerant is evenly distributed on the entire cavity wall of the first flow guide cavity 211 in the circumferential direction, thereby ensuring the uniformity of liquid distribution. Specifically, the liquid distribution section 221 is provided with one circle around the first axis, and all the liquid distribution holes 2211 are provided with one circle around the first axis, so as to avoid the situation where a plurality of liquid distribution holes 2211 spray liquid refrigerant toward the cavity wall of the first flow guide cavity 211 in the same direction, resulting in a large amount of liquid refrigerant flowing down from a certain part of the cavity wall of the first flow guide cavity 211, thereby increasing the uniformity of liquid distribution.

[0061] Further, in the direction of gravity, the position of the first inlet is lower than the position of the second outlet to facilitate the discharge of the gas after rising. It should be understood that in other embodiments, in the direction of gravity, the position of the first inlet may also be higher than the position of the second outlet, or flush with the position of the second outlet, which is not limited here.

[0062] The gas-liquid two-phase refrigerant enters the liquid distribution chamber through the first inlet, and after separation under the action of centrifugal force, it flows out from different liquid distribution holes 2211. In order to ensure that the amount of liquid sprayed on the circumference is consistent, that is, to ensure the uniformity of liquid distribution, it is necessary to set the pressure loss of the refrigerant from the first inlet to each liquid distribution hole 2211 to be consistent, that is, the flow distribution needs to satisfy P1+P2=a certain fixed value. Among them, P1 is the resistance loss along the way, which is related to the length and flow rate of the refrigerant flow; P2 is the local resistance loss, which is the resistance generated by the refrigerant passing through each liquid distribution hole 2211, which is related to the aperture of the liquid distribution hole 2211, because the aperture affects the flow rate, the smaller the aperture, the greater the flow rate, and the greater the resistance.

[0063] The farther the liquid distribution hole 2211 is from the first inlet, the longer the length through which the refrigerant flows, and accordingly, the larger P1 is. At this time, in order to ensure that P1+P2=a certain fixed value, P2 needs to be reduced, and the flow rate needs to be reduced. Accordingly, the aperture of the liquid distribution hole 2211 increases.

[0064] In one embodiment, the liquid distribution holes 2211 are evenly spaced on the liquid distribution section 221, and the diameter of the liquid distribution holes 2211 gradually increases from the end of the liquid distribution section 221 close to the first inlet to the end close to the second outlet. In this way, the pressure loss of the refrigerant from the first inlet to each liquid distribution hole 2211 is consistent, ensuring the uniformity of liquid distribution.

[0065] In another embodiment, the apertures of all the liquid distribution holes 2211 are the same, and the distance between two adjacent liquid distribution holes 2211 gradually decreases from the end of the liquid distribution section 221 close to the first inlet to the end close to the second outlet. In this way, the flow rate of the liquid distribution holes 2211 far from the first inlet of the liquid distribution section 221 is ensured to be equal to the flow rate of the liquid distribution holes 2211 close to the first inlet, thereby ensuring the uniformity of liquid distribution.

[0066] Of course, in other embodiments, for the convenience of processing, the diameters of the liquid distribution holes 2211 can be the same and evenly distributed. The specific number and value of the diameters of the liquid distribution holes 2211 are related to the heat exchange amount or the refrigerant circulation amount, and are not specifically limited here.

[0067] See also Figure 8 The liquid distribution member 22 further includes a first liquid inlet section 222, which is connected to one end of the liquid distribution section 221 provided with a first inlet, and the gas-liquid two-phase refrigerant flows into the liquid distribution section 221 through the first liquid inlet section 222. Specifically, the first inlet has a third central axis, and the first liquid inlet section 222 extends along the third central axis, so that the gas-liquid two-phase refrigerant can be ensured to flow out of the first liquid inlet section 222 and enter the liquid distribution cavity along a tangential direction, and the speed loss is small.

[0068] Continue reading Figure 1 Furthermore, the first liquid inlet section 222 passes through the first flow guide 21 and the shell assembly 10 in sequence to the outside, so that the gas-liquid two-phase refrigerant flows from the throttling device into the first liquid inlet section 222. Specifically, the first flow guide 21 includes a first sub-component and a second sub-component that are separately arranged, and the first sub-component and the second sub-component are connected to form a through hole for the first liquid inlet section 222 to pass through.

[0069] Continue reading Figure 7, the liquid distribution member 22 also includes an air outlet section 223, which is connected to one end of the liquid distribution section 221 having a second outlet, and an air outlet hole 2231 is provided on the air outlet section 223, through which the gaseous refrigerant flows out. Specifically, the air outlet section 223 is arranged in the first flow guide cavity 211, and the gas discharged from the air outlet hole 2231 is discharged into the first flow guide cavity 211, and then enters the third outlet 12 from the first flow guide cavity 211 for discharge. It should be understood that in other embodiments, the air outlet section 223 may also pass through the first flow guide member 21, and at this time, the gas discharged from the air outlet hole 2231 flows back to the first flow guide cavity 211 through the first outlet 212, and then enters the third outlet 12 from the first flow guide cavity 211 for discharge.

[0070] Furthermore, the air outlet hole 2231 is opened on the outer surface of the cavity wall of the assembly cavity 11 facing the first outlet 212 of the air outlet section 223 to prevent the gaseous refrigerant from directly spraying onto the cavity wall of the first guide cavity 211 and interfering with the distribution of the liquid refrigerant, thereby ensuring the uniformity of the distribution.

[0071] Continue reading Figure 1 In one embodiment, the falling film evaporator 100 further includes a second flow guide member 40, which is disposed in the first flow guide member 21, and the liquid distribution section 221 is spirally disposed outside the second flow guide member 40; a second flow guide cavity is disposed in the second flow guide member 40, and a second inlet 41 and a fourth outlet, both of which are connected to the second flow guide cavity, are opened on the second flow guide member 40, the air outlet 2231 and at least part of the outer surface of the heat exchanger are connected to the second inlet 41, and the fourth outlet is connected to the third outlet 12. The gas-liquid two-phase refrigerant flows from the first liquid inlet section 222 to the liquid distribution section 221. When flowing in the liquid distribution cavity, the liquid refrigerant with a higher density flows toward the outer side of the liquid distribution section 221 relative to the gas refrigerant with a lower density, and finally sprays from the liquid distribution hole 2211 to the cavity wall of the first flow guide cavity 211. The liquid refrigerant sprayed on the cavity wall of the first flow guide cavity 211 flows from the first outlet 212 to the surface of the heat exchange tube 30 for heat exchange and evaporation under the action of gravity. The gas formed after evaporation enters the second flow guide cavity from the second inlet 41, and finally passes through the fourth outlet to the third outlet 12 for discharge. The gas refrigerant with a lower density flows out from the gas outlet 2231 and enters between the first flow guide 21 and the second flow guide 40, and then enters the second flow guide cavity from the second inlet 41, and finally passes through the fourth outlet to the gas formed by heat exchange to the third outlet 12 for discharge.

[0072] In one embodiment, the liquid distributor 20 further includes drainage needles 23, and all the drainage needles 23 are arranged at intervals on the end surface of the first flow guide 21 provided with the first outlet 212. Since the drainage needles 23 have a certain length and a certain contact resistance, the liquid column drained by the drainage needles 23 is not easily blown away by the gas formed by evaporation, and has the function of stabilizing the liquid column, thereby facilitating the drainage of the liquid flowing out of the first outlet 212 to the surface of the heat exchange tube 30 for heat exchange.

[0073] Specifically, the drainage needle 23 is in the shape of an inverted triangle, so as to guide the liquid refrigerant to drip. Of course, in other embodiments, the shape of the drainage needle 23 is not limited.

[0074] The distance between each two adjacent drainage needles 23 is equal, and the length of all drainage needles 23 is the same, so as to further ensure the uniformity of liquid distribution. The number of drainage needles 23 is related to the refrigerant flow rate, physical properties, inner diameter of the liquid distribution member 22 and the surface condition of the heat exchange tube 30. The basis for calculation or test is that the liquid refrigerant drained through adjacent drainage needles 23, after expanding through the surface of the heat exchange tube 30, can ensure that the surface of the heat exchange tube 30 between them (corresponding to the surface of the heat exchange tube 30 between two adjacent drainage needles 23) can be completely covered by the liquid film, but not too much refrigerant, resulting in the phenomenon of liquid film accumulation.

[0075] If the flow conductivity of the surface of the heat exchange tube 30 is strong, the number of the drainage needles 23 can be less, that is, the drainage needles 23 are designed to be sparser. If the flow conductivity of the surface of the heat exchange tube 30 is weak, the expansion distance of the liquid refrigerant after dripping onto the heat exchanger is narrow, the number of the drainage needles 23 can be more, that is, the drainage needles 23 are designed to be denser, so as to ensure that the surface of the heat exchange tube 30 is evenly distributed with liquid film. Some heat exchange tubes 30 have good heat exchange but poor flow conductivity, and some heat exchange tubes 30 have good flow conductivity but poor heat exchange. The heat exchange tube 30 will be adjusted according to the actual working conditions to make a choice of the type of heat exchange tube 30.

[0076] In one embodiment, the length of each drainage needle 23 ranges from 10mm to 50mm. As the liquid refrigerant separates from the drainage needle 23 and falls faster and faster under the influence of gravity acceleration, that is, the greater the distance from the bottom of the drainage needle 23 to the top surface of the heat exchange tube 30 (the surface of the heat exchange tube 30 that the liquid refrigerant first contacts when dripping from the drainage needle 23), the greater the speed at which the liquid refrigerant contacts the top surface, and the greater the speed, the liquid refrigerant splashes around. In order for the liquid refrigerant to expand around after reaching the top surface of the heat exchange tube 30 to form a liquid film to wet the surface of the heat exchange tube 30, the flow rate cannot be too large, and the distance from the bottom of the drainage needle 23 to the top surface of the heat exchange tube 30 cannot be too large. Then, if the heat exchange tube 30 is located relatively low, the drainage needle 23 needs to be designed to be longer. In this way, although the dripping speed is faster, there is contact resistance on the drainage needle 23, so it will not be too fast. In addition, there is airflow in the entire space, and the liquid column on the drainage needle 23 is not easily blown crooked by the gas, and the liquid column is more stable. If the heat exchange tube 30 is located relatively high, the drainage needle 23 needs to be designed to be shorter. Generally, if the diameter of the heat exchange tube 30 is set to D, the distance from the bottom of the drainage needle 23 to the top surface of the heat exchange tube 30 is set to about 0.5D. The diameter of the heat exchange tube 30 commonly used at present is mainly in the range of 12.7mm-25.4mm. Then the distance from the bottom of the drainage needle 23 to the top surface of the heat exchange tube 30 is mainly controlled to be in the range of 6mm-13mm. In the embodiment of the present invention, the length of each drainage needle 23 is set to be in the range of 10mm-50mm, which ensures that the distance from the bottom of the drainage needle 23 to the top surface of the heat exchange tube 30 is within the required range, avoiding liquid splashing around, thereby ensuring that the liquid refrigerant reaches the top surface of the heat exchange tube 30 and expands to the surroundings to form a liquid film to wet the surface of the heat exchange tube 30.

[0077] Continue reading Figure 1 The heat exchange tube 30 includes a second liquid inlet section 31, a coil 32 and a first liquid outlet section 33 connected in sequence, the coil 32 spirally extends in the direction of gravity, and the second liquid inlet section 31 and the first liquid outlet section 33 are arranged on the shell assembly 10. The outer surface of the coil 32 is directly opposite to the drainage needle 23, that is, the coil 32 is located on the flow path of the refrigerant flowing out from the first outlet 212. In this way, when the liquid refrigerant flows down from the drainage needle 23, it just flows to the outer surface of the coil 32, so that the liquid film is evenly distributed on the outer surface of the coil 32.

[0078] Specifically, in the direction of gravity, the position of the second liquid inlet section 31 is higher than the position of the first liquid outlet section 33, so that after the hot fluid enters the coil 32 from the second liquid inlet section 31, it flows from the coil 32 to the first liquid outlet section 33 under the action of gravity. It should be understood that in other embodiments, it can also be arranged that in the direction of gravity, the position of the second liquid inlet section 31 is lower than the position of the first liquid outlet section 33.

[0079] Another embodiment of the present invention further provides a liquid distributor 20 included in the falling film evaporator 100, the liquid distributor 20 includes a first flow guide member 21 and a liquid distributor 22, the first flow guide member 21 is provided with a first flow guide cavity 211, the first flow guide member 21 is provided with a first outlet 212 communicating with the first flow guide cavity 211. The liquid distributor 22 includes a liquid distribution section 221, the liquid distribution section 221 is arranged in the first flow guide cavity 211 around a first axis extending in the gravity direction, the liquid distribution cavity is provided in the liquid distribution section 221, and the two end surfaces of the liquid distribution section 221 are respectively provided with a first inlet and a second outlet communicating with the liquid distribution cavity. The surface of the cavity wall of the liquid distribution section 221 facing the first flow guide cavity 211 is provided with liquid distribution holes 2211 connected to the liquid distribution cavity, and the liquid distribution holes 2211 include at least two liquid distribution holes 2211. All liquid distribution holes 2211 are spaced apart from each other in the extension direction of the liquid distribution section 221, and each liquid distribution hole 2211 is constructed to be able to spray liquid flowing out of the liquid distribution cavity onto the cavity wall of the first flow guide cavity 211.

[0080] In the liquid distributor 20 provided in the embodiment of the present invention, when the gas-liquid two-phase refrigerant flows from the first inlet to the liquid distribution cavity, since the liquid distribution section 221 is arranged around a first axis extending in the gravity direction, the gas-liquid two-phase refrigerant will be subjected to centrifugal force when flowing at high speed in the liquid distribution cavity, and the gaseous refrigerant and the liquid refrigerant have different densities, so the centrifugal forces they are subjected to during the flow in the liquid distribution cavity are also different. The liquid refrigerant with a larger density flows toward the outside of the liquid distribution section 221 relative to the gaseous refrigerant with a smaller density, and finally sprays from the liquid distribution hole 2211 onto the cavity wall of the first flow guide cavity 211, and flows to the external heat exchange tube 30 for heat exchange and evaporation. In this way, the liquid distributor 20 can separate the gas-liquid two-phase refrigerant and distribute the liquid refrigerant alone. Compared with the gas-liquid two-phase liquid distribution in the prior art, the interference of the gaseous refrigerant on the liquid distribution is reduced, the uniformity of the liquid distribution is ensured, and thus the heat exchange performance of the falling film evaporator 100 is ensured.

[0081] Another embodiment of the present invention further provides a chiller including the falling film evaporator 100 described above.

[0082] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A liquid distributor, characterized in that: include: A first flow guide member (21) having a first flow guide cavity (211) is provided therein, and a first outlet (212) communicating with the first flow guide cavity (211) is provided on the first flow guide member (21); in the direction of gravity, the first outlet (212) is located below the first flow guide cavity (211); The liquid distributing member (22) comprises a liquid distributing section (221), the liquid distributing section (221) being arranged in the first flow guiding cavity (211) around a first axis, the first axis extending in the gravity direction, a liquid distributing cavity being arranged in the liquid distributing section (221), and a first inlet and a second outlet being arranged at two ends of the liquid distributing section (221) and both being in communication with the liquid distributing cavity; Wherein, at least two liquid distribution holes (2211) communicating with the liquid distribution cavity are provided on the surface of the cavity wall of the liquid distribution section (221) facing the first flow guiding cavity (211); all the liquid distribution holes (2211) are spaced apart from each other in the extension direction of the liquid distribution section (221); When the gas-liquid two-phase refrigerant flows from the first inlet into the liquid distribution cavity, the liquid refrigerant is sprayed from the liquid distribution hole (2211) onto the cavity wall of the first flow guide cavity (211). The liquid refrigerant sprayed onto the cavity wall of the first flow guide cavity (211) flows from the first outlet (212) to the surface of the heat exchange tube (30) under the action of gravity to form a liquid film layer, and the gaseous refrigerant flows out from the second outlet.

2. The liquid dispenser according to claim 1, characterized in that: The liquid distributing section (221) extends spirally around the first axis.

3. The liquid distributor according to claim 1, characterized in that: The liquid distribution section (221) is provided at least once around the first axis, and all the liquid distribution holes (2211) are provided at least once around the first axis.

4. The liquid dispenser according to claim 1, characterized in that: In the gravity direction, the position of the first inlet is lower than the position of the second outlet.

5. The liquid dispenser according to claim 1, characterized in that: The liquid distribution holes (2211) are evenly spaced on the liquid distribution section (221), and the diameters of the liquid distribution holes (2211) gradually increase from one end of the liquid distribution section (221) close to the first inlet to one end close to the second outlet.

6. The liquid dispenser according to claim 1, characterized in that: The apertures of all the liquid distribution holes (2211) are the same, and the distance between two adjacent liquid distribution holes (2211) gradually decreases from one end of the liquid distribution section (221) close to the first inlet to the other end close to the second outlet.

7. The liquid dispenser according to claim 1, characterized in that: The first axis forms a first central axis of the liquid distribution section (221), and the first central axis overlaps with a second central axis of the first flow guiding cavity (211).

8. The liquid dispenser according to claim 1, characterized in that: The liquid distributing member (22) further comprises a first liquid inlet section (222), wherein the first liquid inlet section (222) is connected to an end of the liquid distributing section (221) provided with the first inlet; The first inlet has a third central axis, and the first liquid inlet section (222) extends along the third central axis.

9. The liquid distributor according to any one of claims 1 to 8, characterized in that: The liquid distributor further comprises drainage needles (23), and all of the drainage needles (23) are arranged at intervals from one another on the end surface of the first flow guide member (21) on which the first outlet (212) is provided.

10. The liquid dispenser according to claim 9, characterized in that: The distance between every two adjacent drainage needles (23) is equal, and the lengths of all the drainage needles (23) are the same.

11. The liquid dispenser according to claim 9, characterized in that: The length of each drainage needle (23) ranges from 10 mm to 50 mm.

12. A falling film evaporator, characterized in that: include: A housing assembly (10), wherein an assembly cavity (11) is provided in the housing assembly (10), and a third outlet (12) communicating with the assembly cavity (11) is also provided on the housing assembly (10); a heat exchange tube (30), at least a portion of the heat exchange tube (30) being arranged in the assembly cavity (11); The liquid distributor according to any one of claims 1 to 11, wherein the first flow guide (21) is disposed in the assembly cavity (11), and in the gravity direction, the first flow guide (21) is located above the heat exchange tube (30); Wherein, at least a portion of the heat exchange tube (30) is located on the flow path of the refrigerant flowing out of the first outlet (212), and the second outlet and at least a portion of the outer surface of the heat exchange tube (30) are connected to the third outlet (12).

13. The falling film evaporator according to claim 12, characterized in that: The heat exchange tube (30) comprises a second liquid inlet section (31), a coil (32) and a first liquid outlet section (33) which are connected in sequence, the coil (32) extending spirally in the gravity direction, and the second liquid inlet section (31) and the first liquid outlet section (33) are arranged on the shell assembly (10); The coil (32) is located on the flow path of the refrigerant flowing out of the first outlet (212), and the outer surface of the coil (32) is connected to the third outlet (12).

14. The falling film evaporator according to claim 12, characterized in that: The falling film evaporator further comprises a second flow guide member (40) arranged inside the first flow guide member (21), and the liquid distribution section (221) is arranged outside the second flow guide member (40); a second flow guide cavity is arranged inside the second flow guide member (40), and a second inlet (41) and a fourth outlet are arranged on the second flow guide member (40), both of which are in communication with the second flow guide cavity; the second outlet and at least part of the outer surface of the heat exchange tube (30) are in communication with the second inlet (41), and the fourth outlet is in communication with the third outlet (12).

15. The falling film evaporator according to claim 12, characterized in that: One end of the first flow guide (21) away from the first outlet (212) is connected to the cavity wall of the assembly cavity (11); The liquid distributing member (22) further comprises an air outlet section (223), the air outlet section (223) being connected to one end of the liquid distributing section (221) provided with the second outlet, the air outlet section (223) being located in the first flow guide cavity (211), and the air outlet section (223) being provided with an air outlet hole (2231) on the outer surface of the cavity wall of the assembly cavity (11) directly opposite to the first outlet (212).

16. A chiller, characterized in that: It comprises a falling film evaporator as described in any one of claims 12 to 15.

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