A centrifugal pump for a refrigerator

Abstract

The application relates to the technical field of centrifugal pumps, in particular to a centrifugal pump for a refrigeration device, which comprises a pump body and an impeller arranged in the pump body, the impeller is provided with a face plate and a back plate, an annular buffer cavity is arranged between the back plate and the pump body, the buffer cavity is matched with the impeller, a flow guide hole for fluid communication with the inside of the pump body is arranged on the outer edge of the buffer cavity, the annular buffer cavity is arranged between the back plate of the impeller and the pump body, and the flow guide hole is arranged on the outer edge of the buffer cavity, when water flow is accumulated on the back of the impeller to form high pressure, the high pressure fluid can enter the buffer cavity through the flow guide hole on the buffer cavity, the buffer cavity receives and temporarily stores the high pressure fluid, the high pressure fluid is prevented from continuously gathering on the back of the impeller, the pressure on the impeller in the axial direction is balanced, and the axial direction pressure borne by the impeller is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of centrifugal pumps, in particular to a centrifugal pump for a refrigeration device. BACKGROUND

[0002] With the continuous development and enrichment of global economy and the second industry, the industrial refrigeration field continues to grow, and large refrigeration devices are widely used in chemical industry, manufacturing and many other industrial scenes. As the core equipment for transporting cooling medium in large refrigeration devices, the performance of centrifugal pumps and pumping systems directly affects the overall operation efficiency of the refrigeration system, so the industry's requirements for its efficiency, energy saving, operation stability and low noise characteristics are increasing. At the same time, it is also required to adapt to the installation requirements and working condition adjustment requirements of the refrigeration system to meet the wide range of operating conditions in industrial scenes. In the actual operation process of the centrifugal pump, when the impeller rotates to transport the cooling medium in the low pressure area to the high pressure area, part of the medium will flow into the gap between the impeller and the pump body; Because the front end of the impeller is connected with the low pressure area, obvious pressure difference is easy to form on both sides of the impeller in the axial direction. When the centrifugal pump is used to adapt to the increasing working pressure of industrial refrigeration, the axial pressure difference will further increase, which may not only cause the impeller to move along the axis, but also cause the deformation of the impeller, thereby causing the collision between the impeller and the internal components of the pump body, producing abnormal noise, and even causing the damage of the impeller, directly affecting the operation reliability and service life of the centrifugal pump, and it is difficult to meet the demand of industrial refrigeration system for continuous and stable transportation of cooling medium. For example, Chinese patent CN114483640B discloses a centrifugal pump impeller and a compact industrial refrigeration pump, which forms a circular arc surface by recessing the center position of the impeller back plate towards the inlet, so as to relieve the deformation of the impeller; but this scheme mainly optimizes the anti-deformation ability of the impeller itself structure, and has limited improvement on the root cause of the axial pressure difference of the impeller, and still cannot fully solve the problems of impeller movement and component collision caused by pressure difference, and cannot completely meet the actual demand of industrial refrigeration pump for high efficiency and stable operation. SUMMARY

[0003] In view of the above problems, a centrifugal pump for a refrigeration device is provided, which sets an annular buffer cavity between the impeller back plate and the pump body, and opens a flow guide hole on the outer edge of the buffer cavity. When the water flow is accumulated on the back of the impeller to form high pressure, the high pressure fluid can enter the buffer cavity through the flow guide hole on the buffer cavity, and the buffer cavity receives and temporarily stores these high pressure fluids, avoiding the continuous accumulation of high pressure fluids on the back of the impeller, thereby balancing the pressure on both sides of the impeller and reducing the axial pressure on the impeller.

[0004] To solve the prior art problems, the centrifugal pump for the refrigerator comprises a pump body and an impeller arranged in the pump body, the impeller has a face plate and a back plate, an annular buffer cavity is arranged between the back plate and the pump body, the buffer cavity cooperates with the impeller, a flow guide hole is arranged on the outer edge of the buffer cavity and used for communicating with the inside of the pump body, so that the high-pressure fluid on the back of the impeller is received and temporarily stored during the operation of the pump, and the fluid is divided or guided back when the pressure fluctuates, thereby reducing the axial pressure difference of the impeller.

[0005] Preferably, the buffer cavity comprises a cavity wall fixedly connected with the pump body, an annular sleeve in sliding cooperation with the cavity wall, and the back plate of the impeller, and the annular sleeve can slide along the axis of the fixed cavity wall to form a buffer space that can adapt to the change of the fluid pressure through the surrounding structure, and the cavity wall and the back plate of the impeller have elastic members therebetween.

[0006] Preferably, a plurality of sliding grooves along the axis of the pump body are arranged on the cavity wall, and a sliding rail matched with the sliding grooves is arranged on the annular sleeve, and the annular sleeve is rotationally connected with the back plate of the impeller.

[0007] Preferably, an adjusting hole matched with the flow guide hole is arranged on the annular sleeve, the flow guide hole and the adjusting hole are both elliptical, and the adjusting hole changes the overlapping area with the flow guide hole through the axial sliding of the annular sleeve, so as to adjust the flow rate of the fluid entering and leaving the buffer cavity.

[0008] Preferably, a flow channel is arranged on the back plate of the impeller, one end of the flow channel is in communication with the buffer cavity, and the other end of the flow channel extends to a working area between the face plate and the back plate of the impeller, so as to establish a fluid flow path between the buffer cavity and the working area of the impeller.

[0009] Preferably, the face plate of the impeller is a conical structure.

[0010] Preferably, a flow dividing ring matched with the face plate of the impeller is arranged in the pump body, the flow dividing ring can slide along the axis of the pump body, and a plurality of flow dividing grooves are arranged on the flow dividing ring and surround the axis of the flow dividing ring at equal intervals.

[0011] Preferably, the flow dividing ring is a conical structure, and each flow dividing groove is an S-shaped structure.

[0012] Preferably, a lead screw extending along the axis of the pump body is arranged on the pump body, a flow dividing ring sleeve is arranged on the lead screw and threadedly cooperates with the lead screw, and a plurality of guide rods parallel to the lead screw are arranged in the pump body, and the flow dividing ring sleeve is arranged on the guide rods and slidably cooperates with the guide rods.

[0013] Preferably, a plurality of reinforcing ribs surrounding the axis of the cavity wall at equal intervals are arranged on the side of the cavity wall away from the impeller.

[0014] The beneficial effects of the present application compared with the prior art are as follows:

[0015] 1. The invention sets a ring-shaped buffer cavity between the impeller back plate and the pump body, and sets a flow guide hole on the outer edge of the buffer cavity. When the water flow is accumulated on the back of the impeller to form high pressure, the high pressure fluid can enter the buffer cavity through the flow guide hole on the buffer cavity. The buffer cavity receives and temporarily stores these high pressure fluids, avoiding the continuous accumulation of high pressure fluids on the back of the impeller, thereby balancing the pressure on both sides of the impeller and reducing the axial direction pressure on the impeller. Reduce the friction and wear between the impeller and the internal components of the pump body due to axial movement, avoid affecting the sealing performance of the pump body and the running accuracy of the impeller due to axial offset; at the same time, through the guidance and temporary storage of the buffer cavity to the high pressure fluid, the stability of the fluid pressure in the pump body can be maintained, the continuity of the fluid conveying can be ensured, and the running reliability of the centrifugal pump in the refrigerator system can be improved, so that the refrigerator can stably obtain the required fluid conveying effect, and the overall working performance of the refrigerator is affected by the running fluctuation of the pump body.

[0016] 2. The elastic element between the cavity wall of the buffer cavity and the impeller back plate provides a self-adaptive force balance mechanism for the sliding of the annular sleeve, enhances the adaptation ability of the buffer cavity to pressure fluctuations, balances the pressure on the back of the impeller, and reduces the axial movement tendency of the impeller due to pressure mutation; in addition, the elastic element can absorb part of the pressure impact energy, reduce the sliding friction loss between the annular sleeve and the cavity wall, reduce the wear of the parts, and prolong the service life of the buffer cavity.

[0017] 3. The one-way characteristic of the flow channel ensures the uniqueness of the fluid flow from the buffer cavity to the working area, avoids the interference of backflow to the pressure balance function of the buffer cavity, and ensures that the buffer cavity can continuously and effectively receive and guide the high pressure on the back of the impeller; and the cooperation of the L-shaped structure of the flow channel and the centrifugal force makes the fluid flowing out of the buffer cavity more smoothly into the main fluid motion in the working area, reduces the energy loss caused by fluid turning or collision, and improves the running efficiency of the centrifugal pump. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a perspective structural schematic diagram of a centrifugal pump for a refrigerator.

[0019] Figure 2 It is a perspective structural schematic diagram of a centrifugal pump for a refrigerator.

[0020] Figure 3 It is a cross-sectional structural schematic diagram of a centrifugal pump for a refrigerator.

[0021] Figure 4 It is a cross-sectional structural schematic diagram of a centrifugal pump for a refrigerator.

[0022] Figure 5 It is a perspective structural schematic diagram of the internal structure of a pump body in a centrifugal pump for a refrigerator.

[0023] Figure 6It is an exploded view of a pump body, a buffer cavity and a flow distribution ring in a centrifugal pump for a refrigerator.

[0024] Figure 7 It is a perspective structural schematic view of a flow distribution ring in a centrifugal pump for a refrigerator.

[0025] Figure 8 It is Figure 7 An enlarged view at A in the figure.

[0026] Figure 9 It is a perspective structural schematic view of an impeller in a centrifugal pump for a refrigerator.

[0027] Figure 10 It is a perspective structural schematic view of an impeller and a ring sleeve in a centrifugal pump for a refrigerator.

[0028] Figure 11 It is a perspective structural schematic view of a cavity wall in a centrifugal pump for a refrigerator.

[0029] The figure is marked as: 1, pump body; 11, water inlet; 12, water outlet; 13, buffer cavity; 131, flow guide hole; 132, cavity wall; 1321, sliding groove; 1322, reinforcing rib; 133, ring sleeve; 1331, sliding rail; 1332, adjusting hole; 134, elastic member; 14, flow distribution ring; 141, flow distribution groove; 15, screw rod; 16, guide rod; 2, impeller; 21, face plate; 22, back plate; 221, flow channel. DETAILED DESCRIPTION

[0030] In order to further understand the features, technical means and specific purposes and functions achieved by the present application, the present application is described in further detail below in combination with the drawings and specific embodiments.

[0031] As Figures 1 to 6 shown: a centrifugal pump for a refrigerator, comprising a pump body 1 and an impeller 2 arranged in the pump body 1, the impeller 2 having a face plate 21 and a back plate 22, an annular buffer cavity 13 being arranged between the back plate 22 and the pump body 1, the buffer cavity 13 cooperating with the impeller 2, a flow guide hole 131 being arranged on the outer edge of the buffer cavity 13 for fluid communication with the inside of the pump body 1, so as to receive and temporarily store the high-pressure fluid at the back of the impeller 2 during pump operation, and to distribute or return the fluid when the pressure fluctuates, thereby reducing the axial pressure difference of the impeller 2.

[0032] The side of the pump body 1 is provided with a water inlet 11, and the top of the pump body 1 is provided with a water outlet 12. When the centrifugal pump of the refrigerator is working, the pump body 1 receives fluid through the water inlet 11 on the side, the impeller 2 rotates in the pump body 1 and ejects fluid outward by centrifugal force, and finally the fluid is discharged from the water outlet 12 at the top of the pump body 1; but in actual operation, part of the water flow cannot be completely discharged through the water outlet 12 at one time, and will accumulate in the back area of the impeller 2. With the increase of the accumulated water, the fluid pressure in this area gradually increases, and due to the lack of effective pressure relief structure for this high pressure area in the prior art, the continuously rising pressure will generate an axial thrust on the impeller 2, pushing the impeller 2 to move along the axis direction. By arranging an annular buffer cavity 13 between the back plate 22 of the impeller 2 and the pump body 1, and opening a flow guide hole 131 on the outer edge of the buffer cavity 13, when the water flow accumulates in the back of the impeller 2 to form high pressure, the high pressure fluid can enter the buffer cavity 13 through the flow guide hole 131 on the buffer cavity 13, and the buffer cavity 13 receives and temporarily stores these high pressure fluids, avoiding the continuous accumulation of high pressure fluids in the back of the impeller 2, thereby balancing the pressure on both sides of the impeller 2 and reducing the axial pressure on the impeller 2. Through the above-mentioned mode, the problem of axial movement of the impeller 2 caused by water flow accumulation in the prior art can be effectively solved. On the one hand, it can reduce the friction and wear between the impeller 2 and the internal components of the pump body 1 caused by axial movement, and avoid affecting the sealing performance of the pump body 1 and the running accuracy of the impeller 2 due to axial deviation; on the other hand, through the relief and temporary storage of high pressure fluid by the buffer cavity 13, the stability of the fluid pressure in the pump body 1 can be maintained, the continuity of water flow delivery can be ensured, and the running reliability of the centrifugal pump in the refrigerator system can be improved, so that the refrigerator can stably obtain the required fluid delivery effect, and avoid affecting the overall working performance of the refrigerator due to the running fluctuation of the pump body 1.

[0033] As shown in Figures 3 to 6 and Figures 9 to 11 : the buffer cavity 13 includes a cavity wall 132 fixedly connected with the pump body 1, an annular sleeve 133 in sliding fit with the cavity wall 132, and the back plate 22 of the impeller 2 together form a surrounding structure, the annular sleeve 133 can slide along the axis of the fixed cavity wall 132 to form a buffer space that can adapt to the change of fluid pressure through the surrounding structure, and the cavity wall 132 and the back plate 22 of the impeller 2 have an elastic member 134 therebetween.

[0034] When the impeller 2 rotates to form high pressure on the back of the accumulated water flow, the high pressure fluid enters the enclosed space through the guide hole 131 of the outer edge of the buffer cavity 13, and the pressure pushes the annular sleeve 133 to slide along the axial direction of the pump body 1. At this time, the elastic member 134 deforms with the movement of the annular sleeve 133 and stores elastic potential energy, and the buffer space volume expands to accommodate more high pressure fluid, avoiding the pressure acting directly on the impeller 2; when the fluid pressure in the pump decreases, the elastic member 134 releases the stored potential energy, generating a restoring force to push the annular sleeve 133 to slide in the opposite direction along the axial direction of the pump body 1, so as to reduce the buffer space volume and smoothly return the temporarily stored fluid to the inside of the pump body 1, forming a dynamic response to pressure fluctuations.

[0035] The elastic member 134 between the cavity wall 132 and the back plate 22 of the impeller 2 provides an adaptive force balance mechanism for the sliding of the annular sleeve 133. When the pressure suddenly rises, the deformation of the elastic member 134 can buffer the sliding speed of the annular sleeve 133, avoiding impact or vibration caused by rapid movement, and at the same time, the potential energy storage provides stable power for the reset when the pressure decreases, making the movement of the annular sleeve 133 more stable and controllable. Further enhance the adaptive ability of the buffer cavity 13 to pressure fluctuations, balance the pressure on the back of the impeller 2, reduce the axial movement trend of the impeller 2 due to pressure mutation; in addition, the elastic member 134 can absorb part of the pressure impact energy, reduce the sliding friction loss between the annular sleeve 133 and the cavity wall 132, reduce the wear of the parts, prolong the service life of the buffer cavity 13; at the same time, the more stable pressure regulation process can guarantee the relative position accuracy of the impeller 2 and the internal components of the pump body 1, maintain the sealing performance and operating efficiency of the centrifugal pump, ensure that the refrigeration system obtains continuous and stable fluid delivery, and avoid the influence of pump body 1 operation fluctuations on the refrigeration effect.

[0036] As shown in Figures 3 to 6 and Figures 9 to 11 : The cavity wall 132 is provided with a plurality of sliding grooves 1321 along the axis of the pump body 1, and the annular sleeve 133 is provided with a sliding rail 1331 matched with the sliding groove 1321, and the annular sleeve 133 is rotationally connected with the back plate 22 of the impeller 2.

[0037] When the water flow is accumulated on the back of the impeller 2 to form high pressure, the high pressure fluid enters the space enclosed by the cavity wall 132, the annular sleeve 133 and the back plate 22 of the impeller 2 through the flow guide hole 131 on the outer edge of the buffer cavity 13. The pressure pushes the annular sleeve 133 to slide along the extension direction of the sliding groove 1321, so that the volume of the buffer space is expanded to accommodate the high pressure fluid. At this time, the relative rotation between the annular sleeve 133 and the rotating back plate 22 of the impeller 2 is avoided by the relative rotation cooperation, so as to avoid friction interference; when the fluid pressure in the pump body 1 decreases, the back plate 22 of the impeller 2 drives the annular sleeve 133 to slide reversely along the sliding groove 1321 under the action of the elastic member 134, so that the volume of the buffer space is reduced, and the temporarily stored fluid is guided back to the inside of the pump body 1. During the whole process, the annular sleeve 133 always maintains the single motion form of axial sliding, and the relative rotation with the impeller 2 does not affect the realization of the buffering function.

[0038] The cooperation of the sliding groove 1321 and the sliding rail 1331 not only provides precise sliding guidance for the annular sleeve 133, but also avoids the rotation of the annular sleeve 133 with the impeller 2 by limiting the circumferential rotation, so as to eliminate the additional friction or motion interference that may be generated by the synchronous rotation of the two. At the same time, the relative rotation cooperation between the annular sleeve 133 and the back plate 22 of the impeller 2 further reduces the wear between components; the stable sliding track ensures that the adjustment of the volume of the buffer space is more controllable, so that the receiving, temporary storage and guiding back process of the high pressure fluid is more stable, which can more effectively balance the pressure on the back of the impeller 2 and reduce the axial movement tendency of the impeller 2; in addition, the cooperation relationship between the structures reduces the risk of failure caused by complex motion form, prolongs the service life of the buffer cavity 13, ensures the continuous and stable operation of the centrifugal pump in the refrigeration system, and maintains the efficient fluid conveying effect.

[0039] As shown in Figures 3 to 6 and Figures 9 to 11 : The annular sleeve 133 is provided with an adjusting hole 1332 matched with the flow guide hole 131, and the flow guide hole 131 and the adjusting hole 1332 are both elliptical. The adjusting hole 1332 changes the overlapping area with the flow guide hole 131 with the axial sliding of the annular sleeve 133, so as to adjust the flow of fluid in and out of the buffer cavity 13.

[0040] When the back of the impeller 2 is under high pressure due to water accumulation, the annular sleeve 133 slides along the axial direction of the pump body 1 under the pressure, and the overlapping area of the adjusting hole 1332 on the annular sleeve 133 and the flow guide hole 131 on the cavity wall 132 increases with the sliding, so that more high-pressure fluid enters the buffer cavity 13 through the overlapping area to quickly relieve the pressure accumulation at the back of the impeller 2; when the fluid pressure in the pump decreases, the annular sleeve 133 slides reversely under the action of the elastic member 134, the overlapping area of the adjusting hole 1332 and the flow guide hole 131 decreases, reducing the flow of fluid into the buffer cavity 13, while the temporarily stored fluid in the buffer cavity 13 can be smoothly returned to the inside of the pump body 1 through the reduced overlapping area, avoiding the impact on the impeller 2 caused by the excessive speed of backflow. The cooperation of the oval adjusting hole 1332 and the flow guide hole 131 makes the change of the overlapping area more linear when they slide relative to each other, and the flow regulation is more stable. Compared with other shapes, the oval hole can provide a wider flow regulation range under the same sliding stroke, adapting to different amplitudes of pressure fluctuations.

[0041] Through the cooperation of the flow guide hole 131 and the adjusting hole 1332, the sliding of the annular sleeve 133 changes the overlapping area to accurately regulate the flow, so that the receiving and returning of the buffer cavity 13 to the high-pressure fluid better meets the needs of pressure changes, avoiding the stress fluctuation of the impeller 2 caused by flow mutation, further reducing the axial movement of the impeller 2; the linear flow regulation characteristic reduces the turbulence and energy loss of the fluid passing through the hole, improving the pressure regulation efficiency of the buffer cavity 13; the oval adjusting hole 1332 and the flow guide hole 131 reduce the stress concentration of the hole edge, reduce the wear of the hole caused by fluid impact, prolong the service life of the component, ensure the long-term stable function of the buffer cavity 13, and thus ensure the continuous and efficient operation of the centrifugal pump in the refrigeration system, maintaining stable fluid conveying effect.

[0042] As shown in Figures 3 to 6 and Figures 9 to 11 : the back plate 22 of the impeller 2 is provided with a flow channel 221, one end of the flow channel 221 is connected with the buffer cavity 13, and the other end of the flow channel 221 extends to the working area between the face plate 21 and the back plate 22 of the impeller 2, so as to establish a fluid flow path between the buffer cavity 13 and the working area of the impeller 2.

[0043] The buffer cavity 13 receives and temporarily stores the high-pressure fluid at the back of the impeller 2 through the flow guide hole 131, and the temporarily stored fluid can flow to the working area of the impeller 2 through the one-way flow channel 221 on the back plate 22 of the impeller 2. It should be noted that the flow channel 221 is one-way, only supports the flow of the buffer cavity 13 to the panel 21 and the back plate 22 of the impeller 2, and the flow channel 221 is preferably L-shaped, and the outlet of the flow channel 221 is arranged along the radial direction of the impeller 2. When the fluid enters the working area through the flow channel 221, it can directly comply with the direction of the centrifugal force generated by the rotation of the impeller 2, and is quickly driven by the centrifugal force of the impeller 2 and merged into the main fluid, and is thrown to the water outlet 12 together with the main fluid. At the same time, the one-way characteristic of the flow channel 221 can prevent the fluid in the working area from flowing back into the buffer cavity 13, ensuring that the pressure regulation in the buffer cavity 13 is not disturbed by the fluctuation of the fluid in the working area, and maintaining the stable control of the buffer cavity 13 on the pressure at the back of the impeller 2.

[0044] The one-way characteristic of the flow channel 221 ensures the uniqueness of the fluid flow from the buffer cavity 13 to the working area, avoids the interference of backflow to the pressure balance function of the buffer cavity 13, and ensures that the buffer cavity 13 can continuously and effectively receive and dredge the high pressure at the back of the impeller 2. The L-shaped structure of the flow channel 221 cooperates with the centrifugal force, so that the fluid flowing out of the buffer cavity 13 can more smoothly merge into the main fluid movement in the working area, reduce the energy loss caused by fluid turning or colliding, and improve the operating efficiency of the centrifugal pump. At the same time, the orderly one-way flow further balances the pressure at the back of the impeller 2 and the working area, reduces the axial movement trend of the impeller 2 due to pressure difference, reduces the friction and wear between components, prolongs the service life of the centrifugal pump, ensures its continuous and stable fluid conveying in the refrigeration system, and maintains the stability of the refrigeration effect.

[0045] As shown in Figures 3 to 6 and Figures 9 to 11 : the panel 21 of the impeller 2 is a conical structure.

[0046] In the operation of the centrifugal pump, the conical panel 21 of the impeller 2 rotates with the impeller 2. When the fluid enters from the central area of the impeller 2, the inclined shape of the conical panel 21 can conform to the tendency of the fluid driven outward by the centrifugal force, and gradually guide the fluid to the edge direction of the impeller 2. With the continuous rotation of the impeller 2, the conical panel 21 continuously guides the fluid, so that the fluid can more smoothly complete the transition of the flow path along the arc of the conical surface in the flow process from the center to the edge, reducing the blocking phenomenon of the fluid in the flow process. The conical panel 21 cooperates with the blades of the impeller 2 to make the fluid flow inside the impeller 2 more in line with the trajectory of the centrifugal motion, reduce the impact strength and turbulence degree between the fluid and the panel 21, thereby reducing energy loss and improving the fluid conveying efficiency of the centrifugal pump; at the same time, smoother fluid flow can reduce noise and vibration caused by fluid impact, and reduce the wear of the panel 21 of the impeller 2, prolong the service life of the impeller 2, thereby ensuring the continuous and stable operation of the centrifugal pump in the system such as a refrigerator, and providing power support for efficient fluid conveying of the system.

[0047] As shown in Figures 3 to 8 The pump body 1 is provided with a flow dividing ring 14 matched with the panel 21 of the impeller 2. The flow dividing ring 14 can slide along the axis direction of the pump body 1, and a plurality of flow dividing grooves 141 are arranged around the axis of the flow dividing ring 14.

[0048] The pump body 1 is provided with a flow dividing ring 14 matched with the conical panel 21 of the impeller 2 near the water inlet 11. The flow dividing ring 14 is provided with a plurality of flow dividing grooves 141 arranged at equal intervals around the axis of the flow dividing ring 14, and the flow dividing ring 14 can slide along the axis direction of the pump body 1. When the centrifugal pump is running, the high-pressure fluid flows back from the gap between the panel 21 of the impeller 2 and the pump body 1 to the low-pressure area, i.e. the water inlet 11 end of the pump body 1. At this time, the flow dividing ring 14 forms an annular gap with the panel 21 of the impeller 2. When the flow dividing ring 14 slides in the axial direction, the relative position of the flow dividing ring 14 and the panel 21 of the impeller 2 changes, so that the width of the annular gap changes uniformly. That is, when the flow dividing ring 14 moves towards the panel 21 of the impeller 2, the gap narrows, and the restriction on the backflow fluid increases. When the flow dividing ring 14 moves away from the panel 21 of the impeller 2, the gap expands, and the resistance to backflow decreases. At the same time, when the backflow high-pressure fluid flows through the flow dividing ring 14, it will be guided by the flow dividing grooves 141 to form an orderly flow, and smoothly enter the low-pressure area along the direction of the flow dividing grooves 141.

[0049] The adjustment of the annular gap between the flow distribution ring 14 and the face plate 21 of the impeller 2 is realized through the axial sliding fit of the flow distribution ring 14, and the resistance can be dynamically adapted according to the pressure of the backflow fluid, so as to avoid excessive backflow and increased energy loss caused by too large gap, and prevent friction or flow blockage caused by too small gap; the flow distribution groove 141 guides the flow direction of the backflow fluid, reduces the direct impact of the fluid on the face plate 21 of the impeller 2, reduces the axial force for pushing the impeller 2 to move along the axis, thereby relieving the wear of the impeller 2 caused by the axial movement, and ensuring the stability of the relative position of the impeller 2 and the pump body 1; in addition, the orderly flow guidance reduces the turbulence and vortex in the backflow process, reduces the energy loss, improves the operating efficiency of the centrifugal pump, and makes the fluid flow more smoothly, reduces the interference of pressure fluctuation on the overall operation of the pump body 1, ensures that the refrigerator system can obtain continuous and stable fluid delivery, and maintains high refrigeration effect.

[0050] As shown in Figures 3 to 8 : the flow distribution ring 14 is a conical structure, and each flow distribution groove 141 is an S-shaped structure.

[0051] When the centrifugal pump operates, the flow distribution ring 14 slides along the axis direction of the pump body 1, and the annular gap between the conical structure of the flow distribution ring 14 and the face plate 21 of the impeller 2 uniformly changes with the sliding, so as to adjust the backflow amount of the high-pressure fluid; at the same time, the backflow high-pressure fluid enters the annular gap and is guided by the S-shaped flow distribution groove 141 to flow along the arc path of the S-shaped groove. The curvature of the S-shaped structure is adapted to the motion trajectory of the fluid when backflowing, so that the fluid forms a smooth flow state in the groove, avoids turbulence caused by sudden change of the flow channel 221, and further suppresses the axial displacement of the impeller 2, thereby relieving the wear of the components; at the same time, the orderly flow guidance reduces the turbulence in the backflow process, improves the fluid flow efficiency, makes the centrifugal pump operate more smoothly, helps to prolong the service life of the equipment, and ensures that the refrigerator system obtains continuous and stable fluid delivery effect.

[0052] As shown in Figures 3 to 8 : the pump body 1 is provided with a lead screw 15 extending along the axis direction thereof, the flow distribution ring 14 is sleeved on the lead screw 15 and threadedly fitted with the lead screw 15, and the pump body 1 is further provided with a plurality of guide rods 16 parallel to the lead screw 15, and the flow distribution ring 14 is sleeved on the guide rods 16 and slidably fitted with the guide rods 16.

[0053] When it is necessary to adjust the annular gap between the flow distribution ring 14 and the impeller 2, the lead screw 15 extending along the axis of the pump body 1 can be driven to rotate; since the flow distribution ring 14 is threadedly fitted with the lead screw 15, and the flow distribution ring 14 is sleeved on the guide rods 16 parallel to the lead screw 15 and can slide along the guide rods 16, the rotation of the lead screw 15 will be converted into the linear movement of the flow distribution ring 14 along the axis direction of the pump body 1, thereby changing the size of the annular gap between the flow distribution ring 14 and the impeller 2, so as to adjust the backflow amount of the high-pressure fluid through the gap.

[0054] The threaded cooperation of the screw rod 15 and the split ring 14 can precisely control the axial displacement of the split ring 14, so that the adjustment of the annular gap is more accurate, thereby stably controlling the backflow amount and effectively balancing the pressure at the back of the impeller 2; the guide rod 16 provides stable guidance for the axial movement of the split ring 14, avoiding the deflection or jamming of the split ring 14 during movement, ensuring that the relative position of the split ring 14 and the impeller 2 is always accurate, and guaranteeing the reliability of the gap adjustment; by precisely and stably adjusting the annular gap, both the energy loss caused by improper backflow amount and the wear of the impeller 2 caused by axial force fluctuation can be reduced, thereby improving the operating efficiency and stability of the centrifugal pump, and further ensuring the continuous and stable fluid delivery in the refrigerator system.

[0055] As shown in Figure 5 : a plurality of reinforcing ribs 1322 are arranged on the side of the cavity wall 132 away from the impeller 2 and are equidistantly arranged around the axis thereof.

[0056] During the operation of the centrifugal pump, the cavity wall 132 as the fixed part of the buffer cavity 13 will continuously bear the pressure transmitted by the high-pressure fluid in the buffer cavity 13, especially the side of the cavity wall 132 away from the impeller 2, although it is not directly in contact with the impeller 2 or the sliding annular sleeve 133, the pressure will still be conducted to this side through the body of the cavity wall 132, which may cause local deformation of the cavity wall 132. The plurality of reinforcing ribs 1322 arranged on the side of the cavity wall 132 away from the impeller 2 and equidistantly arranged around the axis thereof can uniformly disperse the pressure borne by the cavity wall 132 to each reinforcing rib 1322 through the structural support of the reinforcing ribs 1322, avoiding the concentration of pressure in a certain local area of the cavity wall 132, and the equidistant distribution of the reinforcing ribs 1322 along the axis can ensure the balance of the force in the circumferential direction of the cavity wall 132, preventing the cavity wall 132 from being deformed in a deflection manner due to uneven force, thereby maintaining the stability of the overall structure of the buffer cavity 13 and not affecting the smoothness of the sliding of the annular sleeve 133 along the cavity wall 132 and the adjustment function of the buffer cavity 13 to the fluid pressure. The presence of the reinforcing ribs 1322 does not need to thicken the cavity wall 132 to improve the strength, while ensuring the structural stability, the overall weight and volume of the cavity wall 132 can be controlled, avoiding increasing the overall burden of the pump body 1, and ensuring that the centrifugal pump maintains a compact structure and efficient operating state in the refrigerator system, thereby providing reliable support for the stability of fluid delivery.

[0057] The above embodiments only express one or several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A centrifugal pump for a chiller characterized by, The pump comprises a pump body (1) and an impeller (2) arranged in the pump body (1), the impeller (2) has a face plate (21) and a back plate (22), an annular buffer cavity (13) is arranged between the back plate (22) and the pump body (1), the buffer cavity (13) is matched with the impeller (2), a flow guide hole (131) is arranged on the outer edge of the buffer cavity (13) and is in fluid communication with the inside of the pump body (1), so as to receive and temporarily store the high-pressure fluid at the back of the impeller (2) during the operation of the pump, and to divide or return the fluid when the pressure fluctuates, thereby reducing the axial pressure difference of the impeller (2); The buffer cavity (13) comprises a cavity wall (132) fixedly connected with the pump body (1), an annular sleeve (133) in sliding cooperation with the cavity wall (132), and the back plate (22) of the impeller (2) jointly forms a surrounding structure, the annular sleeve (133) can slide along the axis of the fixed cavity wall (132) to form a buffer space that can adapt to the change of fluid pressure through the surrounding structure, and the cavity wall (132) and the back plate (22) of the impeller (2) are provided with elastic members (134).

2. A centrifugal pump for a chiller according to claim 1 wherein, A plurality of sliding grooves (1321) along the axis of the pump body (1) are arranged on the cavity wall (132), and the annular sleeve (133) is provided with sliding rails (1331) matched with the sliding grooves (1321), and the annular sleeve (133) is rotationally connected with the back plate (22) of the impeller (2).

3. A centrifugal pump for a chiller according to claim 1 wherein, The annular sleeve (133) is provided with an adjusting hole (1332) matched with the flow guide hole (131), and the flow guide hole (131) and the adjusting hole (1332) are both elliptical, the adjusting hole (1332) changes the overlapping area with the flow guide hole (131) by axial sliding of the annular sleeve (133), so as to adjust the flow rate of fluid entering and leaving the buffer cavity (13).

4. A centrifugal pump for a chiller according to claim 1 wherein, The back plate (22) of the impeller (2) is provided with a flow channel (221), one end of the flow channel (221) is in communication with the buffer cavity (13), and the other end of the flow channel (221) extends to a working area between the face plate (21) and the back plate (22) of the impeller (2), so as to establish a fluid flow path between the buffer cavity (13) and the working area of the impeller (2).

5. A centrifugal pump for a chiller according to claim 1 wherein, The face plate (21) of the impeller (2) is a conical structure.

6. A centrifugal pump for a chiller according to claim 5 wherein, A flow dividing ring (14) matched with the face plate (21) of the impeller (2) is arranged in the pump body (1), the flow dividing ring (14) can slide along the axis of the pump body (1), and a plurality of flow dividing grooves (141) are arranged on the flow dividing ring (14) and are equidistantly arranged around the axis of the flow dividing ring (14).

7. A centrifugal pump for a chiller according to claim 6 wherein, The flow dividing ring (14) is a conical structure, and each flow dividing groove (141) is an S-shaped structure.

8. A centrifugal pump for a chiller according to claim 6 wherein, A lead screw (15) extending along the axis of the pump body (1) is arranged on the pump body (1), the flow dividing ring (14) is sleeved on the lead screw (15) and is in threaded cooperation with the lead screw (15), and a plurality of guide rods (16) parallel to the lead screw (15) are arranged in the pump body (1), the flow dividing ring (14) is sleeved on the guide rods (16) and is in sliding cooperation with the guide rods (16).

9. A centrifugal pump for a chiller according to claim 1 wherein, A plurality of reinforcing ribs (1322) equidistantly arranged around the axis of the cavity wall (132) are arranged on the side of the cavity wall (132) away from the impeller (2).

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