CN113776238B

CN113776238B - condenser

Info

Publication number: CN113776238B
Application number: CN202010523695.7A
Authority: CN
Inventors: 张平; 汤庆华; 杨胜梅
Original assignee: York Wuxi Air Conditioning and Refrigeration Co Ltd; Johnson Controls Technology Co
Current assignee: York Wuxi Air Conditioning and Refrigeration Co Ltd; Johnson Controls Technology Co
Priority date: 2020-06-10
Filing date: 2020-06-10
Publication date: 2023-10-10
Anticipated expiration: 2040-06-10
Also published as: CN113776238A

Abstract

The application provides a condenser which comprises a condenser shell, an air inlet pipe, a heat exchange pipe group and a vibration device. The vibration device comprises an initiating component and a transmission component, wherein the initiating component is connected with the transmission component. The initiating element is movable by being impacted by the refrigerant vapor flowing from the inlet tube into the condenser housing. The transmission component is sleeved outside at least part of the heat exchange tubes in the heat exchange tube group, and the transmission component is configured to transmit the motion of the initiating component to at least part of the heat exchange tubes so as to cause the vibration of at least part of the heat exchange tubes. In the process of heat exchange between the heat exchange tube and the refrigerant, high-temperature refrigerant steam is easy to condense on the outer wall of the heat exchange tube, and the heat resistance of the outer side of the heat exchange tube is increased. The vibration device can drive part of the heat exchange tubes to vibrate by utilizing the pulsation energy of the refrigerant steam, and reduces or removes the refrigerant liquid film on the outer wall of the heat exchange tubes through vibration, thereby improving the heat exchange efficiency of the heat exchange tubes and the refrigerant steam.

Description

Condenser

Technical Field

The application relates to the technical field of condensers.

Background

The condenser is used as an important heat exchange component of the large and medium-sized water chilling unit and is important to the performance of the unit. The condenser belongs to one of heat exchangers, and a plurality of heat exchange tubes are arranged in the condenser. The refrigerant vapor from the compressor is capable of exchanging heat with the plurality of heat exchange tubes in the condenser, whereby the refrigerant vapor is condensed and is converted from a gaseous state to a liquid state. Because the refrigerant vapor entering the condenser from the compressor is superheated, film-like condensation forms on the outer wall of the heat exchange tube after the high temperature refrigerant vapor contacts the wall surface of the heat exchange tube below its saturation temperature. The heat resistance of the outer wall of the heat exchange tube can be increased by the refrigerant liquid film formed by the refrigerant steam on the outer wall of the heat exchange tube, heat exchange between the refrigerant steam and the heat exchange tube is hindered, and therefore heat exchange efficiency between the refrigerant steam and the heat exchange tube is reduced.

Disclosure of Invention

The application aims to provide a condenser, which can utilize airflow impact energy of refrigerant steam entering the condenser from a compressor to trigger vibration of a part of heat exchange tubes in the condenser, so as to reduce or remove a refrigerant liquid film attached on the outer wall of the part of heat exchange tubes, and solve the problem of heat exchange deterioration in the condenser caused by condensation of the liquid film on the outer wall of the heat exchange tubes.

In order to achieve the above object, the present application provides a condenser including a condenser housing, an intake pipe, a heat exchange tube group, and a vibration device. The interior of the condenser housing forms an accommodation space. The air inlet pipe is arranged on the condenser shell, and the inner part of the air inlet pipe is in fluid communication with the accommodating space. The heat exchange tube group is arranged in the accommodating space and comprises a plurality of heat exchange tubes. The vibration device is arranged in the accommodating space and comprises an initiating component and a transmission component. The initiating member is provided in the accommodating space and is configured to be movable by being impacted by refrigerant vapor flowing from the intake pipe into the accommodating space. The transmission component is connected to the initiating component and sleeved on the outer side of at least part of the heat exchange tubes, and the transmission component is configured to transmit the motion of the initiating component to the at least part of the heat exchange tubes so as to cause the vibration of the at least part of the heat exchange tubes.

The condenser of the preceding claim, wherein the plurality of heat exchange tubes comprises a plurality of upper heat exchange tubes and a plurality of lower heat exchange tubes, and the plurality of upper heat exchange tubes are positioned above the plurality of lower heat exchange tubes. The transmission part comprises an upper transmission part and a lower transmission part, the lower transmission part is sleeved on the outer sides of the plurality of lower heat exchange pipes and is connected to the initiating part through the upper transmission part, wherein the upper transmission part is configured such that the motion of the initiating part can be transmitted to the plurality of lower heat exchange pipes by bypassing the plurality of upper heat exchange pipes.

The condenser of the previous claim, wherein said upper driving part comprises at least one driving rod, and a space for said at least one driving rod to pass through is provided in the array of said plurality of upper heat exchange tubes.

The condenser as claimed in the preceding claim, said at least one transmission rod comprising an elastic segment made of an elastic material.

The condenser of the present invention, wherein the upper transmission part comprises a transmission plate, a plurality of avoidance holes are formed in the transmission plate, and the plurality of upper heat exchange tubes are correspondingly accommodated in the plurality of avoidance holes, wherein the size of the plurality of avoidance holes is respectively larger than the size of the cross section of the plurality of upper heat exchange tubes, so that the plurality of upper heat exchange tubes are always not contacted with the corresponding avoidance holes in the vibration process of the transmission part.

The condenser as claimed in the preceding claim, comprising a gas baffle disposed below the air inlet pipe;

the initiating component comprises a vibrating plate, one end of the vibrating plate is connected with the air baffle plate, the vibrating plate is connected with the upper transmission part, and the vibrating plate can be driven to vibrate by refrigerant steam flowing in from the air inlet pipe.

The condenser of the preceding claim, wherein the baffle comprises a bottom plate extending parallel to the plurality of heat exchange tubes, and wherein the vibration plate is inclined obliquely upward relative to the bottom plate of the baffle.

The condenser of the preceding claim, comprising a gas baffle arranged below the air inlet pipe, the gas baffle being provided with a through hole therein. The initiating member includes a rotary vane disposed in the through hole through a rotary shaft and connected to the upper transmission part through the rotary shaft, wherein the rotary vane is capable of being driven to rotate together with the rotary shaft by refrigerant vapor flowing in from the intake pipe.

The condenser as claimed in the preceding claim, the driving part further comprising a cam coupled to the rotation shaft such that the cam can eccentrically rotate with the rotation of the rotation shaft; the top of the upper transmission part is provided with a receiving part, and the cam is rotatably received in the receiving part, so that the eccentric rotation of the cam can drive the upper transmission part to move up and down.

The condenser as claimed in the preceding claim, further comprising a supercooler provided at the bottom of the accommodating space, the driving part being supported by the supercooler.

The application provides a vibration device in a condenser, wherein the vibration device comprises an initiating component and a transmission component, and the initiating component is connected with the transmission component. The vibration device of the application utilizes the air flow pulsation of the refrigerant steam from the compressor to drive the initiating component to move, and the driving component is used for transmitting the movement energy of the initiating component to part of the heat exchange tubes in the condenser, thereby realizing the vibration of part of the heat exchange tubes. The vibration of the heat exchange tube can accelerate the falling of the condensed refrigerant liquid film on the outer wall of the heat exchange tube, thereby playing the role of reducing or removing the liquid film on the outer wall of the heat exchange tube and improving the heat exchange efficiency of the heat exchange tube in the condenser.

Drawings

FIG. 1 is a schematic diagram of a condenser 100 to which embodiments of the present application are applicable;

fig. 2A shows an arrangement structure of a vibration device 200 of a first embodiment of the present application;

FIG. 2B is an enlarged view of FIG. 2A in the area of vibration device 200;

fig. 3 is a radial sectional view of the vibration device 200 shown in fig. 2A in the condenser 100;

fig. 4 is a radial sectional view of a vibration device 200 of a second embodiment of the present application in a condenser 100;

Fig. 5 shows a partial structure of a vibration device 200 according to a third embodiment of the present application;

fig. 6 shows a perspective view of a vibration device 200 according to a fourth embodiment of the present application;

fig. 7 and 8 show two different connection structures of the cam 601 and the upper transmission part 205 in the vibration device 200 of fig. 6, respectively.

Detailed Description

Various embodiments of the present application are described below with reference to the accompanying drawings, which form a part hereof. It is to be understood that, although directional terms, such as "front", "rear", "upper", "lower", "left", "right", etc., may be used in the present application to describe various example structural parts and elements of the present application, these terms are used herein for convenience of description only and are determined based on the example orientations shown in the drawings. Since the disclosed embodiments of the application may be arranged in a variety of orientations, these directional terms are used by way of illustration only and are in no way limiting.

Fig. 1 is a schematic view of a condenser 100 to which embodiments of the present application are applicable. As shown in fig. 1, the condenser 100 is a shell-and-tube condenser including a condenser housing 101, an intake pipe 102, a baffle 106, a heat exchange tube group 103, a subcooler 104, a discharge pipe 105, and a pair of tube sheets 107. The condenser case 101 is substantially cylindrical, and an accommodation space 111 is formed therein. The air baffle 106, the heat exchange tube group 103, and the subcooler 104 are all disposed in the accommodating space 111. The intake pipe 102 is also cylindrical and is provided at the top of the condenser casing 101. The interior of the intake pipe 102 is in fluid communication with the accommodation space 111 of the condenser housing 101, so that refrigerant vapor from a compressor (not shown) can enter the accommodation space 111 inside the condenser housing 101 through the intake pipe 102.

The heat exchange tube group 103 includes a plurality of heat exchange tubes 113, and each heat exchange tube 113 has an elongated tubular shape. The plurality of heat exchange tubes 113 are arranged side by side, and the length direction of each heat exchange tube 113 coincides with the length direction of the condenser case 101, thereby forming an array of heat exchange tubes 113. The plurality of heat exchange tubes 113 includes a plurality of upper heat exchange tubes 114 and a plurality of lower heat exchange tubes 115, and the plurality of upper heat exchange tubes 114 are positioned above the plurality of lower heat exchange tubes 115, so that the plurality of heat exchange tubes 113 form an upper array and a lower array. The heat exchange tube group 103 is provided to promote heat exchange of the refrigerant vapor in the accommodating space 111 of the condenser case 101, and the refrigerant vapor after the heat exchange is condensed into a gas-liquid mixture state. A pair of tube sheets 107 are provided at both ends in the longitudinal direction of the condenser casing 101, respectively, and are connected to both ends in the longitudinal direction of the plurality of heat exchange tubes 113. A plurality of heat exchange tubes 113 are fixedly disposed in the accommodating space 111 of the condenser casing 101 by a pair of tube sheets 107.

The air baffle 106 is connected to the inner wall of the condenser case 101 and is fixedly disposed below the air intake pipe 102. As shown in fig. 1, the air baffle 106 is located between the air intake pipe 102 and the heat exchange tube group 103 with a certain interval from both the air intake pipe 102 and the heat exchange tube group 103. The provision of the gas barrier 106 in the condenser housing 101 can prevent the refrigerant vapor from the intake pipe 102 from directly striking the heat exchange tube group 103, thereby reducing damage to the heat exchange tube group 103 by the refrigerant vapor.

The subcooler 104 is disposed below the heat exchange tube group 103 at the bottom of the accommodating space 111 of the condenser casing 101. The liquid refrigerant condensed by the heat exchange of the heat exchange tube group 103 in the liquid outlet tube 105 moves downward by gravity, and enters the subcooler 104. The liquid refrigerant becomes a subcooled liquid after continuing to exchange heat at subcooler 104. A drain pipe 105 is provided below the subcooler 104 at the bottom of the condenser housing 101. The supercooled refrigerant liquid after heat exchange by the supercooler 104 can flow out of the condenser case 101 from the liquid outlet pipe 105.

During heat exchange between the refrigerant vapor and the heat exchange tube group 103, since the refrigerant vapor entering the condenser case 101 from the compressor through the intake tube 102 is superheated, film-like condensation of the refrigerant vapor occurs on the outer walls of the heat exchange tubes 113 when the high-temperature refrigerant vapor contacts the outer walls of the heat exchange tubes 113 below the saturation temperature thereof. As shown in fig. 1, since the refrigerant liquid film condensed on the outer walls of the plurality of heat exchange tubes 113 drops downward by gravity, the thickness of the refrigerant liquid film increases as the number of rows of the heat exchange tubes 113 increases, and the thickness of the refrigerant liquid film attached to the outer walls of the lower heat exchange tubes 115 is greater than the thickness of the refrigerant liquid film attached to the outer walls of the upper heat exchange tubes 114. However, the refrigerant film condensed on the outer wall of the heat exchange tube 113 has heat conduction resistance, which reduces heat exchange efficiency between the refrigerant vapor and the heat exchange tube 113, and the thicker the refrigerant film, the greater the heat conduction resistance. That is, the thicker the film of refrigerant liquid condensed on the outer wall of the heat exchange tube 113, the lower the heat exchange efficiency of the heat exchange tube 113. As can be seen from this, the heat exchange efficiency of the plurality of lower heat exchange tubes 115 is low due to the thicker refrigerant liquid film adhering to the outer wall.

Fig. 2A shows an arrangement structure of a vibration device 200 of a first embodiment of the present application, showing a positional relationship of the vibration device 200 with respect to an intake pipe 102, a gas baffle 106, and a subcooler 104 in a condenser 100. Fig. 2B is an enlarged view of fig. 2A in the area of the vibration device 200. Fig. 3 is a radial sectional view of the vibration device 200 shown in fig. 2A in the condenser 100. In order to prevent excessive liquid refrigerant from adhering to the plurality of lower heat exchange tubes 115 to form a liquid film and further prevent the heat exchange performance of the condenser 100 from being lowered, the present application provides a vibration device 200 in the accommodating space 111 inside the condenser 100. The vibration device 200 of the present embodiment is suitable for the shell-and-tube condenser 100 in screw and centrifugal chiller units, and can utilize the exhaust pulsation of the screw compressor or the exhaust of the centrifugal compressor as a vibration source, thereby avoiding the cost of additionally adding a vibrator.

As shown in fig. 2A, the vibration device 200 is disposed between the intake pipe 102 and the subcooler 104. The vibration device 200 includes an initiating component 201, a transmission component 202, and a support component 204. In the present embodiment, the initiating component 201 includes a vibration plate 203, and one end of the vibration plate 203 is connected to the gas barrier 106 so that the refrigerant vapor flowing toward the gas barrier 106 can impinge on the vibration plate 203. As shown in fig. 2B, the baffle 106 includes a bottom plate 214 and two side plates 216. The bottom plate 214 is disposed parallel to the extending direction of the plurality of heat exchange tubes 113 and is located directly below the intake pipe 102. The bottom plate 214 has a length direction which coincides with the length direction of the condenser casing 101, and two side plates 216 are connected to both side edges in the width direction of the bottom plate 214. As shown in fig. 3, two side plates 216 extend obliquely upward from the bottom plate 214, respectively, and are attached to the inner wall of the condenser case 101. The above-described arrangement of the gas barrier 106 enables the bottom plate 214 to be fixed directly below the intake pipe 102, so that the refrigerant vapor from the intake pipe 102 flows directly to the bottom plate 214. Since the air baffle 106 extends entirely along the longitudinal direction of the condenser casing 101, the air baffle 106 can guide the refrigerant vapor to move in the longitudinal direction of the condenser casing 101. The vibration plate 203 is obliquely disposed upward with respect to the bottom plate 214 of the air baffle 106. One end 213 of the vibration plate 203 is connected to the air baffle 106, and the other end 217 is a free end. In the present embodiment, one end 213 of the vibration plate 203 is connected to one side 223 in the length direction of the bottom plate 214, so that the refrigerant vapor guided through the gas barrier 106 can impinge on the vibration plate 203. The vibration plate 203 vibrates under the driving of the refrigerant vapor flow impact. The first embodiment of the present application uses the vibration plate 203 as the initiating component 201, and drives the initiating component 201 to vibrate by the refrigerant vapor discharged from the compressor. In the embodiment of the present application, the vibration plate 203 is made of spring steel, which can meet the environmental requirement of high temperature inside the condenser 100, and has certain rigidity and elasticity.

The transmission member 202 is connected to the initiating element 201 to conduct vibrations from the initiating element 201. As shown in fig. 2B and 3, the transmission member 202 includes an upper transmission portion 205 and a lower transmission portion 206. The upper transmission part 205 is connected between the vibration plate 203 and the lower transmission part 206, and is capable of transmitting vibration energy from the vibration plate 203 to the lower transmission part 206. In this embodiment, the upper transmission part 205 is a transmission rod 215, and the transmission rod 215 is made of a metal material capable of providing rigidity. The transmission rod 215 is vertically disposed up and down perpendicular to the extending direction of the heat exchange tube group 103. One end of the transmission rod 215 is connected to the lower surface of the vibration plate 203, and the other end is connected to the lower transmission portion 206. The connection between the transmission rod 215 and the vibration plate 203 is provided to help convert vibration of the vibration plate 203 in a range of amplitude into up-and-down movement of the transmission rod 215. As shown in fig. 3, the upper transmission portion 205 is located substantially in the array of the plurality of upper heat exchange tubes 114 and is not in contact with any one of the upper heat exchange tubes 114; the lower transmission part 206 is located at the array position of the plurality of lower heat exchange tubes 115 and is sleeved outside the plurality of lower heat exchange tubes 115. To accommodate the placement of the upper transmission portion 205 in the array of upper heat exchange tubes 114, the array of upper heat exchange tubes 114 is divided into left and right sub-arrays 301 with a gap between the left and right sub-arrays 301 to provide space for the transmission rod 215 to pass through. The arrangement of the space between the two sub-arrays 301 of the upper heat exchange tube 114 also allows a downward flow path for the refrigerant vapor to more easily enter the lower heat exchange tube 115 via this path, thereby reducing the amount of refrigerant deposited on the outer walls of the upper heat exchange tube 114 and enhancing the heat exchange between the refrigerant vapor and the lower heat exchange tube 115.

The lower transmission portion 206 is substantially plate-shaped, is arranged in the radial direction of the condenser case 101, is perpendicular to the extending direction of the heat exchange tube group 103, and is substantially on the same plane as the upper transmission portion 205. In this embodiment, the plate surface of the lower transmission portion 206 is provided with a plurality of receiving holes 218 arranged side by side. Each of the receiving holes 218 penetrates through the thickness direction of the lower transmission part 206, and the number of the receiving holes 218 is the same as that of the lower heat exchange tubes 115, and the size and shape of the receiving holes 218 are matched with those of the cross section of the lower heat exchange tubes 115. The above-described arrangement of the lower transmission portion 206 enables each of the plurality of lower heat exchange tubes 115 to be accommodated in a corresponding one of the accommodating holes 218, so that vibration energy obtained from the vibration plate 203 by the lower transmission portion 206 can be transmitted to the plurality of lower heat exchange tubes 115. That is, the vibration of the vibration plate 203 can be transferred to the plurality of lower heat exchange tubes 115 while bypassing the plurality of upper heat exchange tubes 114, thereby driving the plurality of lower heat exchange tubes 115 to vibrate up and down. Because the lower transmission part 206 directly drives the lower heat exchange tube 115 to vibrate, in order to ensure the vibration amplitude of the lower heat exchange tube 115, parameters such as the material, shape, size and the like of the lower transmission part 206 can be optimally adjusted, so that the natural frequency of the lower transmission part 206 falls in the frequency range of the pulsation of the refrigerant steam airflow, and the lower transmission part 206 can resonate with the compressor exhaust pulsation, thereby ensuring that a liquid film attached to the outer wall of the heat exchange tube 113 effectively falls off. In this embodiment, the amplitude of vibration of the lower transmission portion 206 is about 1-2mm. The up-down vibration of the plurality of lower heat exchange tubes 115 can promote the refrigerant liquid film attached to the outer walls of the plurality of lower heat exchange tubes 115 to drop downwards, thereby reducing the thickness of the liquid film on the outer walls of the lower heat exchange tubes 115 and improving the heat exchange efficiency of the plurality of lower heat exchange tubes 115. In some embodiments, the lower transmission portion 206 may mount a receiving hole protector on an inner diameter of the receiving hole 218. The accommodating hole protecting device is made of elastic materials and is connected between the accommodating hole 218 and the lower heat exchange tube 115, so that the contact area between the accommodating hole 218 and the lower heat exchange tube 115 accommodated therein is increased, the shearing force of the accommodating hole 218 on the lower heat exchange tube 115 is reduced, and the loss of the lower heat exchange tube 115 caused by the vibration of the lower transmission part 206 is reduced.

The support member 204 is disposed at the bottom of the lower transmission portion 206. As shown in fig. 2B and 3, the support member 204 includes two support rods 219, and both support rods 219 are formed to extend downward from the bottom of the lower transmission portion 206. The distance between the two support rods 219 is approximately the same as the width of the supercooler 104, so that the transmission part 202 of the vibration device 200 can be supported on both sides of the supercooler 104 through the two support rods 219. In some embodiments, the support members 204 may also be supported on the inner wall of the condenser housing 101. The support members 204 may be provided to provide additional support and positioning for the vibration device 200. In other embodiments, the vibration device 200 may not include the support members 204.

Fig. 4 is a radial sectional view of a vibration device 200 of a second embodiment of the present application in the condenser 100. Similar to the vibration device 200 of the first embodiment of the present application, the vibration device 200 of the second embodiment also includes an initiating member 201, a transmitting member 202, and a supporting member 204. The structural arrangement of the initiating component 201, the supporting component 204, and the lower transmission portion 206 in the transmission component 202 of the second embodiment is identical to that of the first embodiment, and the description of the vibration device 200 of the first embodiment is omitted herein. Unlike the vibration device 200 of the first embodiment which employs one transmission rod 215 as the upper transmission portion 205 of the transmission member 202, the upper transmission portion 205 of the vibration device 200 of the second embodiment has two transmission rods 215. As shown in fig. 4, the two transmission rods 215 are vertically disposed and are located on the same radial plane of the condenser housing 101, and the upper end is connected to the vibration plate 203 and the lower end is connected to the lower transmission portion 206. The upper ends of the two transmission rods 215 are respectively connected to the lower surface of the vibration plate 203 at the same height, and are respectively disposed at two opposite side positions of the vibration plate 203, so that the two transmission rods 215 have the maximum interval therebetween. The further spacing between the two transmission rods 215 helps to transfer vibrations from the vibration plate 203 to both sides of the lower transmission portion 206 arranged in the radial direction of the condenser case 101, and can effectively strengthen the vibration transfer of the upper transmission portion 205 to the vibration plate 203. In order to adapt the arrangement of the two transmission rods 215 in the plurality of upper heat exchange tube 114 arrays, the plurality of upper heat exchange tube 114 arrays are divided into three sub-arrays 301, and two gaps are arranged between the three sub-arrays 301 and are respectively used for providing a space for the two transmission rods 215 to pass through. The two voids provided in the array of upper heat exchange tubes 114 in this embodiment provide a downward flow path for the refrigerant vapor, enhancing heat exchange between the refrigerant vapor and lower heat exchange tubes 115. The second embodiment is also capable of transmitting the vibration of the vibration plate 203 to the plurality of lower heat exchange tubes 115 by bypassing the plurality of upper heat exchange tubes 114 with respect to the structural arrangement of the upper transmission portion 205, thereby driving the plurality of lower heat exchange tubes 115 to vibrate up and down.

Fig. 5 shows a partial structure of a vibration device 200 according to a third embodiment of the present application. Similar to the structure of the vibration device 200 of the second embodiment, the vibration device 200 of the third embodiment of the present application also adjusts the structure of the transmission member 202 based on the vibration device 200 of the first embodiment, so that fig. 5 only shows the structure of the transmission member 202 and the support member 204 connected thereto in the vibration device 200 of the third embodiment. The structural arrangement of the initiating component 201, the supporting component 204, and the lower transmission portion 206 in the transmission component 202 in the third embodiment is identical to that in the first embodiment, and the description of the vibration device 200 in the first embodiment is omitted herein for brevity. Unlike the vibration device 200 of the first and second embodiments each employing the transmission rod 215 as the upper transmission portion 205 of the transmission member 202, the upper transmission portion 205 of the vibration device 200 of the third embodiment is a transmission plate 501. As shown in fig. 5, the transmission plate 501 is vertically disposed perpendicular to the extending direction of the heat exchange tube group 103, and the plane on which the transmission plate 501 is located is substantially located on the radial surface of the condenser casing 101. The transmission plate 501 is provided with a plurality of avoiding holes 511, and the number of the avoiding holes 511 is the same as that of the upper heat exchange tubes 114, so that the plurality of upper heat exchange tubes 114 can be correspondingly accommodated in the plurality of avoiding holes 511. The size of each of the escape holes 511 is respectively larger than the size of the cross section of one of the upper heat exchange tubes 114 correspondingly accommodated therein, so that the plurality of upper heat exchange tubes 114 are not always in contact with the corresponding escape holes 511 during vibration of the transmission member 202. That is, the vibration of the driving plate 501 does not affect the upper heat exchange tube 114. Therefore, the third embodiment maintains the state that the upper heat exchange tubes 114 are fully distributed in the condenser case 101, and the vibration of the vibration plate 203 is transferred to the plurality of lower heat exchange tubes 115 by bypassing the plurality of upper heat exchange tubes 114, so as to drive the plurality of lower heat exchange tubes 115 to vibrate up and down. In this embodiment, the vibration amplitude of the transmission part 206 driven by the initiating component 201 is about 1-2mm, so that the aperture of the avoiding hole 511 is set to be 1-2mm larger than the outer diameter of the heat exchange tube 113.

Fig. 6 shows a perspective view of a vibration device 200 according to a fourth embodiment of the present application. As shown in fig. 6, the vibration device 200 of the fourth embodiment includes an initiating member 201, a transmitting member 202, and a supporting member 204. The overall structure of the air baffle 106 associated with the fourth embodiment vibration device 200 is similar to that of the air baffle 106 associated with the first, second and third embodiments, including a bottom plate 214 and two side plates 216. Wherein the bottom plate 214 is located directly below the intake pipe 102, and two side plates 216 are disposed obliquely upward with respect to the bottom plate 214 and are attached to the inner wall of the condenser casing 101. Unlike the air baffle 106 of the first, second, and third embodiments, the air baffle 106 of the fourth embodiment is provided with a through hole 602 and a mounting groove 608 on the bottom plate 214. To more clearly illustrate the structural relationship between the bottom plate 214 and the initiating component 201, two side plates 216 attached to either side of the bottom plate 214 are omitted from FIG. 6, showing the bottom plate 214 configuration of the gas barrier 106.

As shown in fig. 6, the through hole 602 of the base plate 214 is circular for receiving the initiating component 201 of the vibration device 200. The initiating component 201 includes a rotating blade 603, the rotating blade 603 being semi-circular in shape. The semicircular rotary blade 603 has a shape and size matching those of the through hole 602 of the bottom plate 214, and the circular shape corresponding to the semicircular rotary blade 603 is slightly smaller than that corresponding to the through hole 602, so that the rotary blade 603 can be accommodated in the through hole 602, and the semicircular rotary blade 603 is concentrically arranged with the circular through hole 602. The initiating component 201 of the present embodiment includes two rotating blades 603, and in other embodiments, other numbers of rotating blades 603 may be provided.

As shown in fig. 6, the mounting groove 608 is formed in a long shape as a whole, and is hollowed out in the thickness direction of the bottom plate 214. The mounting groove 608 communicates with the through hole 602, and the mounting groove 608 extends from the through hole 602 to one side 223 in the length direction of the bottom plate 214. The extending direction of the mounting groove 608 on the bottom plate 214 is consistent with the length direction of the bottom plate 214, and the extension line of the mounting groove 608 on the through hole 602 can pass through the center of the circle where the through hole 602 is located.

The transmission member 202 of the vibration device 200 includes a rotation shaft 604, a cam 601, an upper transmission portion 205, and a lower transmission portion 206. The rotation shaft 604 is disposed on the plane of the base plate 214, and the rotation shaft 604 is accommodated in the through hole 602 and the mounting groove 608. One end of the rotation shaft 604 is rotatably connected to an edge position of the through hole 602, and the remaining portion of the rotation shaft 604 extends from the through hole 602 to the mounting groove 608, and continues from the mounting groove 608 to the outside of the bottom plate 214. The other end of the rotation shaft 604 extending to the outside of the bottom plate 214 is connected to the cam 601, so that kinetic energy of the rotation shaft 604 can be transmitted to the cam 601. As shown in fig. 6, since the extending direction of the mounting groove 608 on the bottom plate 214 coincides with the longitudinal direction of the bottom plate 214, the extending direction of the rotation shaft 604 mounted in the mounting groove 608 also coincides with the longitudinal direction of the bottom plate 214. That is, the extending direction of the rotation shaft 604 coincides with the axial direction of the condenser case 101. Since the extension line of the mounting groove 608 on the through hole 602 passes through the center of the circle in which the through hole 602 is located, the rotation shaft 604 mounted in the mounting groove 608 can also pass through the center of the circle in which the through hole 602 is located. The arrangement of the rotation shaft 604 in the through hole 602 divides the through hole 602 into two symmetrical semicircular sub-through holes. As shown in fig. 6, the rotation shaft 604 is connected to the rotation blades 603, and the two rotation blades 603 are symmetrically disposed with respect to the rotation shaft 604, so that the rotation blades 603 can be disposed in the through holes 602 through the rotation shaft 604, and the rotation blades 603 can be rotated around the rotation shaft 604 in the through holes 602. When the rotating blade 603 rotates to a certain position, the plane on which the rotating blade 603 is located can be flush with the air baffle 106. The above arrangement enables the rotary vane 603 to be impacted by the flow of the refrigerant vapor from the intake pipe 102 at the same time as the air baffle 106. When the refrigerant vapor flows toward the louver 106 and impinges on the upper surface of the louver 106 and the rotating blades 603 mounted in the through holes 602 of the louver 106, the rotating blades 603 are driven by the refrigerant vapor to rotate together with the rotating shaft 604. Since the rotation shaft 604 is connected to the cam 601, the rotation of the rotation blade 603 can simultaneously drive the rotation shaft 604 and the cam 601 to rotate.

In the fourth embodiment of the present application, a through hole 602 is provided in the bottom plate 214 of the air baffle 106, and a set of rotating blades 603 is correspondingly provided in the through hole 602. Other numbers of through holes 602, such as two, three, etc., may also be provided in the base plate 214 in other embodiments. A set of rotating blades 603 is disposed in each of the plurality of through holes 602, so that the vibration device 200 of the fourth embodiment can drive the rotation shaft 604 and the cam 601 of the transmission member 202 to move by rotating the plurality of sets of rotating blades 603.

As shown in fig. 6, the cam 601 has a substantially circular cake shape, and is connected to an end portion of the rotary shaft 604 on a side extending from the bottom plate 214. The position where the cam 601 is connected to the rotation shaft 604 is located on the left side surface 607 of the cam 601. The left side surface 607 is substantially circular, and the connection position of the end portion of the rotation shaft 604 at the left side surface 607 of the cam 601 is deviated from the center of the circle in which the left side surface 607 is located. When the rotation shaft 604 is rotated by the rotation blades 603, the cam 601 is eccentrically rotated by the eccentric connection of the cam 601 fixed to the rotation shaft 604.

The upper transmission part 205 is vertically disposed in the receiving space 111 of the condenser case 101, and the upper transmission part 205 is located below the cam 601. The connection between the upper transmission part 205 and the cam 601 is provided to convert the rotational movement of the cam 601 into the up-and-down movement of the upper transmission part 205. As shown in fig. 6, the upper transmission part 205 is a transmission rod 215, and the transmission rod 215 is in a round rod shape and is connected between the cam 601 and the lower transmission part 206. The transmission rod 215 includes an elastic section 605, and when the transmission rod 215 moves up and down, the elastic section 605 is configured to amplify the movement amplitude of the transmission rod 215 so that the lower transmission part 206 obtains greater kinetic energy. In this embodiment, the elastic section 605 is a spring section, and in other embodiments, the elastic section 605 may be made of other elastic materials.

Fig. 7 and 8 show two connection structures of the cam 601 and the upper transmission part 205 in the vibration device 200 of fig. 6, respectively. The vibration device 200 of the fourth embodiment can achieve kinetic energy transmission between the cam 601 and the upper transmission portion 205 using either one of the structures of fig. 7 and 8.

Fig. 7 shows a first configuration in which the cam 601 is connected to the upper transmission 205. As shown in fig. 7, the left surface 607 and the right surface 609 of the cam 601 are both planar. The top of the upper transmission part 205 is provided with a receiving part 701, and the receiving part 701 is a groove 610 recessed downward from the top surface of the upper transmission part 205. The inner walls of the groove 610 on the left and right sides are also planar, corresponding to the planar structure of the left and right side surfaces of the cam 601. The shape and size of the groove 610 are adapted to the shape and size of the cam 601 so that the lower portion of the cam 601 can be accommodated in the groove 610. During the eccentric rotation of the cam 601, the lower part of the cam 601 is constantly changed in a state of being suddenly raised or lowered, but the lower part of the cam 601 is always accommodated in the groove 610 regardless of how it is changed. That is, during the eccentric rotation of the cam 601, the lower portion of the cam 601 always abuts on the top of the upper transmission part 205, exerting a downward pressure on the receiving part 701 of the upper transmission part 205. Even when the lower portion of the cam 601 moves to a higher position in the time-wise downward process, the cam 601 abuts the top of the upper transmission portion 205. As can be seen in connection with fig. 6, the provision of the resilient section 605 in the upper transmission part 205 ensures that the upper transmission part 205 is always in a compressed state. As shown in fig. 7, the groove 610 is provided to prevent the cam 601 from slipping off the top end of the upper transmission part 205 during eccentric rotation. When the cam 601 is driven by the rotation shaft 604 to perform eccentric movement, the driving force of the cam 601 abutting on the top of the upper transmission portion 205 can cause the upper transmission portion 205 to move up and down.

Fig. 8 shows a second configuration in which the cam 601 is connected to the upper transmission 205. As shown in fig. 8, the cam 601 in the second structure is provided with a flange 611 around the outer peripheral position. The flange 611 protrudes from the left surface 607 and the right surface 609 of the cam 601, respectively, so that neither the left surface 607 nor the right surface 609 is planar. The top of the upper transmission part 205 is provided with a receiving part 701, and the receiving part 701 is a groove 610 recessed downward from the top surface of the upper transmission part 205. The left and right inner walls of the groove 610 are respectively provided with stoppers 801 at the top end position of the upper transmission part 205 in conformity with the structure of the flange 611 around the outer circumference of the cam 601. The two blocking members 801 extend oppositely from the inner walls of the left and right sides of the groove 610, respectively, and a space is provided between the two blocking members 801, so that an accommodating space of the cam 601 can be provided. The shape and size of the groove 610 are adapted to the shape and size of the cam 601 so that the lower portion of the cam 601 can be accommodated in the groove 610. When the lower portion of the cam 601 is received in the recess 610, the two stops 801 at the top of the upper transmission 205 are located on the flange 611 of the cam 601 received in the recess 610. During the eccentric rotation of the cam 601, the lower part of the cam 601 is constantly transformed, but due to the limited effect of the two stops 801 on the flange 611 of the cam 601, the lower part of the cam 601 is always housed in the groove 610, whatever the transformation. That is, during eccentric rotation of the cam 601, when the lower portion of the cam 601 is located at a higher position, the upper end of the flange 611 of the cam 601 applies upward tension to the two blocking members 801 of the upper transmission part 205, and the two blocking members 801 of the upper transmission part 205 block the flange 611 of the cam 601 from further moving upward, thereby preventing the cam 601 from slipping out of the receiving part 701 of the upper transmission part 205. When the lower portion of the cam 601 is located at a lower position, the lower portion of the cam 601 abuts against the top of the upper transmission portion 205, and the arrangement of the left and right side walls of the groove 610 can prevent the cam 601 from slipping off the top end of the upper transmission portion 205. With the second structure in which the cam 601 is connected to the upper transmission part 205, stable connection between the cam 601 and the upper transmission part 205 can be ensured without the cam 601 always applying downward pressure to the upper transmission part 205. In this embodiment, the elastic section 605 may not be provided in the upper transmission portion 205. As shown in fig. 8, due to the relatively locked connection between the cam 601 and the upper transmission part 205, the cam 601 can cause the upper transmission part 205 to move up and down when the cam 601 is driven by the rotation shaft 604 to perform an eccentric motion.

As shown in fig. 6, in order to further secure the connection between the cam 601 and the upper transmission part 205 and prevent the upper transmission part 205 from having a large vibration amplitude in the horizontal direction, the vibration device 200 of the fourth embodiment is provided with a limiting device 606 sleeved outside the transmission rod 215. As shown in fig. 6, the limiting device 606 has a rectangular collar shape, and the limiting device 606 is fixedly connected to the inner wall of the condenser housing 101 through a connecting member (not shown). The movement range of the driving rod 215 defined by the limiting device 606 outside the driving rod 215 is slightly larger than the outer diameter of the driving rod 215, so that the driving rod 215 can only move under the limiting effect of the limiting device 606 in the horizontal direction, and the possibility that the driving rod 215 is separated from the connection of the cam 601 is greatly reduced.

The vibration device 200 of the fourth embodiment is identical to the first, second and third embodiments in terms of the arrangement of the lower transmission portion 206 and the support member 204 at the bottom of the lower transmission portion 206, and thus will not be described herein. The vibration device 200 of the fourth embodiment is provided with rotatable rotating blades 603 as the initiating member 201 on the air baffle 106. When the refrigerant vapor impinges on the louver 106 from top to bottom, the rotating blades 603 are driven by the refrigerant vapor to rotate the rotating shaft 604. The rotation of the rotation shaft 604 is then transmitted to the cam 601, and the cam 601 eccentrically connected to the rotation shaft 604 performs eccentric rotation by the drive of the rotation shaft 604, so that the lowest point of the cam 601 is left unattended, and periodically reciprocates. Since the lower portion of the cam 601 is rotatably received by the receiving portion 701 at the top of the upper transmission portion 205, the upper transmission portion 205 is also subjected to the driving force from the cam 601 to reciprocate up and down as the lowest point of the cam 601 is reciprocated up and down. That is, as the upper transmission part 205 reciprocates up and down, the lower transmission part 206 connected below the upper transmission part 205 is also driven to reciprocate up and down, thereby driving the plurality of heat exchange tubes 113 sleeved in the lower transmission part 206 to vibrate up and down. The vibration device 200 of the fourth embodiment converts the rotational movement of the rotary blade 603 into the up-and-down reciprocating movement by the crank link mechanism of the transmission member 202.

Various embodiments of the present application provide a plurality of circular receiving holes 218 in the lower transmission portion 206, and each receiving hole 218 is configured to receive one heat exchange tube 113 of the plurality of lower heat exchange tubes 115. In other embodiments, a plurality of elongated receiving holes 218 may be provided in the lower transmission portion 206. Each of the elongated receiving holes 218 may simultaneously receive a plurality of heat exchange tubes 113 in the same row of the plurality of lower heat exchange tubes 115, so long as the lower transmission portion 206 can be sleeved outside the plurality of lower heat exchange tubes 115, and the plurality of lower heat exchange tubes 115 are driven to vibrate by the lower transmission portion 206.

The vibration device 200 of the present application uses the discharge pulsation of the compressor to excite the motion of the initiating component 201. The present application also employs a crank-link structure in the vibration device 200 to convert the motion of the initiating component 201 into the up-and-down motion of the lower transmission portion 206. The up-and-down movement of the lower transmission part 206 provides a vibration source for the part of the heat exchange tube 113 sleeved in the lower transmission part 206, thereby driving the part of the heat exchange tube 113 to vibrate up and down along with the lower transmission part 206. The vibration of a part of the heat exchange tubes 113 can promote the falling of the refrigerant liquid film attached to the outer surface of the heat exchange tubes 113, so that the thickness of the liquid film on the outer wall of the heat exchange tubes 113 is reduced, and the heat exchange efficiency of the heat exchange tube group 103 is improved. Since the thickness of the liquid film attached to the outer wall of the heat exchange tube 113 disposed below is thicker than the thickness of the liquid film attached to the outer wall of the heat exchange tube 113 disposed above, various embodiments of the present application are directed to the partial heat exchange tubes 113 disposed in the middle and lower portions of the condenser case 101, i.e., the lower heat exchange tube 115. The vibration device 200 can more efficiently utilize the impact energy of the refrigerant vapor only for the design of the lower heat exchange tube 115, and can improve the situation that the external thermal resistance of the lower heat exchange tube 115 is overlarge due to the overlarge thickness of the liquid film condensed on the outer wall of the lower heat exchange tube 115.

The vibration device 200 of the embodiment of the application is suitable for the shell-and-tube condenser 100 in screw type and centrifugal water chilling units, and is particularly suitable for screw type water chilling units. Since the rotor cavity volume change speed of the screw compressor is periodically changed, the discharge of the screw compressor is periodically pulsed discharge. The exhaust frequency which can be achieved by the screw compressor is 40 Hz-300 Hz, and when the screw unit is operated in a variable frequency mode, the exhaust pulsation frequency of normal operation is 90 Hz-300 Hz. In some embodiments, the thickness, shape of the lower drive section 206 may be designed such that its natural frequency falls within the range of 40Hz to 90 Hz. When the screw compressor is in normal operation, the pulsation frequency of the refrigerant vapor does not cause resonance of the lower transmission part 206, and only when the screw compressor is not in a normal operation state, the lower transmission part 206 can generate resonance, thereby realizing vibration with larger vibration amplitude. In some embodiments, the lower transmission 206 may be configured to: only when the lower transmission part 206 resonates with the discharge pulsation of the compressor, the lower transmission part 206 drives the heat exchange pipe 113 to vibrate. This may be accomplished by adjusting the size of the receiving aperture 218 of the lower transmission portion 206. The above arrangement can reduce the amount of liquid film adhering to the outer wall of the lower heat exchange tube 115 and reduce the influence of vibration of the lower heat exchange tube 115 on the function and structure of the condenser 100. That is, in this embodiment, the vibration night removing function of the vibration device 200 does not need to be performed all the time, but only needs to be performed periodically with the operation of the screw compressor, thereby reducing the influence of the vibration on the heat exchange tube 113 while securing the liquid removing effect. It should be noted that the natural frequency of the lower transmission portion 206 after being optimally designed should not be equal to the natural frequency of the heat exchange tube 113 to avoid causing resonance of the heat exchange tube 113.

When the vibration device 200 of the embodiment of the present application is applied to the condenser 100 in the screw-type water chiller, the vibration device 200 may be installed to perform vibration liquid removal in the following manner: after the water chilling unit operates for 3 hours, the control logic enables the exhaust frequency of the screw compressor to be reduced to 40 Hz-90 Hz. At this time, the exhaust pipe outputs exhaust pulsation of 40 Hz-90 Hz to drive the initiating component 201 to move. The motion of the initiating component 201 is transferred to the driving component 202 through the crank linkage structure so that the lower driving part 206 obtains pulsation in the frequency range of 40Hz to 90Hz. When the natural frequency of the lower transmission part 206 is consistent with the discharge frequency of the compressor, the lower transmission part 206 resonates to drive the lower heat exchange tube 115 to vibrate, so that a liquid film attached to the outer surface of the lower heat exchange tube 115 falls off. After 10 minutes, the control logic causes the discharge frequency of the screw compressor to rise to the normal operating frequency, at which time the discharge frequency of the compressor bypasses the natural frequency of the lower drive section 206, the lower drive section 206 no longer resonates with the discharge pulsations of the compressor, and the lower heat exchange tube 115 is at rest. In this embodiment, the vibration device 200 does not operate in the normal operation mode of the water chiller for 3 hours, and the vibration device 200 drives the lower heat exchange tube 115 to vibrate only in the abnormal operation mode of the water chiller for 10 minutes, so as to realize the function of vibration liquid removal. That is, every 3 hours the chiller is normally operated, the vibration device 200 is operated for 10 minutes, and periodically reduces or removes the liquid film attached to the outer wall of the lower heat exchange tube 115. The above-mentioned operation mode of the vibration device 200 can periodically realize the function of removing liquid in the whole operation process of the water chiller, and hardly causes additional influence on the normal operation of the water chiller. In other embodiments, the vibration device 200 may employ other liquid removal cycle modes.

Although only a few features of the application have been shown and described, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the application.

Claims

1. A condenser, characterized in that the condenser (100) comprises:

a condenser housing (101), wherein an accommodating space (111) is formed inside the condenser housing (101);

an air intake pipe (102), the air intake pipe (102) being provided on the condenser housing (101), an interior of the air intake pipe (102) being in fluid communication with the accommodation space (111);

a heat exchange tube group (103), the heat exchange tube group (103) being disposed within the accommodating space (111), the heat exchange tube group (103) including a plurality of heat exchange tubes (113);

a gas baffle plate (106), wherein the gas baffle plate (106) is positioned between the air inlet pipe (102) and the heat exchange tube group (103) and is spaced from the air inlet pipe (102) and the heat exchange tube group (103) at a certain interval; and

-a vibration device (200), the vibration device (200) being arranged within the accommodation space (111), the vibration device (200) comprising:

an initiating member (201), the initiating member (201) being provided in the accommodating space (111) and being provided so as to be movable by being impacted by refrigerant vapor flowing from a compressor into the accommodating space (111) from the intake pipe (102) and heat exchanging with the heat exchange tube group of the condenser in the accommodating space (111), the initiating member (201) including a vibration plate (203), one end of the vibration plate (203) being connected to the gas baffle plate (106) so that the refrigerant vapor flowing toward the gas baffle plate (106) can impinge on the vibration plate (203); and

-a transmission member (202), the transmission member (202) being connected to the initiating member (201) and being sleeved outside at least part of the heat exchange tubes (113) of the number of heat exchange tubes (113), the transmission member (202) being configured to be able to transmit a movement of the initiating member (201) to the at least part of the heat exchange tubes (113) to cause vibration of the at least part of the heat exchange tubes (113).

2. The condenser of claim 1, wherein:

the plurality of heat exchange tubes (113) comprise a plurality of upper heat exchange tubes (114) and a plurality of lower heat exchange tubes (115), and the plurality of upper heat exchange tubes (114) are positioned above the plurality of lower heat exchange tubes (115);

the transmission part (202) comprises an upper transmission part (205) and a lower transmission part (206), wherein the lower transmission part (206) is sleeved outside the plurality of lower heat exchange tubes (115) and is connected to the initiating part (201) through the upper transmission part (205), and the upper transmission part (205) is configured such that the motion of the initiating part (201) can be transmitted to the plurality of lower heat exchange tubes (115) by bypassing the plurality of upper heat exchange tubes (114).

3. The condenser of claim 2, wherein:

the upper transmission part (205) comprises at least one transmission rod (215), and a space for the at least one transmission rod (215) to pass through is arranged in the array of the plurality of upper heat exchange tubes (114).

4. A condenser according to claim 3, wherein:

the at least one drive rod (215) comprises an elastic section (605), the elastic section (605) being made of an elastic material.

5. The condenser of claim 2, wherein:

the upper transmission part (205) comprises a transmission plate (501), a plurality of avoidance holes (511) are formed in the transmission plate (501), the plurality of upper heat exchange tubes (114) are correspondingly contained in the plurality of avoidance holes (511), wherein the sizes of the plurality of avoidance holes (511) are respectively larger than the sizes of the cross sections of the plurality of upper heat exchange tubes (114), so that the plurality of upper heat exchange tubes (114) are not contacted with the corresponding avoidance holes (511) all the time in the vibration process of the transmission part (202).

6. The condenser according to any one of claims 2 to 5, wherein:

the air baffle (106) is arranged below the air inlet pipe (102); the vibration plate (203) is connected to the upper transmission part (205).

7. The condenser according to any one of claims 1 to 5, wherein:

the condenser (100) further comprises a supercooler (104), the supercooler (104) is arranged at the bottom of the accommodating space (111), and the transmission part (202) is supported by the supercooler (104).

8. The condenser of claim 1, wherein:

the air baffle (106) comprises a bottom plate (214) extending parallel to the plurality of heat exchange tubes (113), and the vibration plate (203) is inclined obliquely upward relative to the bottom plate (214) of the air baffle (106).

9. A condenser, characterized in that the condenser (100) comprises:

the air baffle (106), the air baffle (106) is arranged below the air inlet pipe (102), and a through hole (602) is arranged in the air baffle (106);

an initiating member (201), the initiating member (201) being provided within the accommodating space (111) and being provided so as to be movable by being impacted by refrigerant vapor from a compressor flowing from the intake pipe (102) into the accommodating space (111) and heat exchanging with the heat exchange tube group of the condenser in the accommodating space (111); and

A transmission member (202), the transmission member (202) comprising an upper transmission portion (205) and a lower transmission portion (206),

the transmission part (202) is connected to the initiating part (201) through the upper transmission part (205) and sleeved outside at least part of the heat exchange tubes (113) in the plurality of heat exchange tubes (113), and the transmission part (202) is configured to be capable of transmitting the motion of the initiating part (201) to the at least part of the heat exchange tubes (113) so as to cause the vibration of the at least part of the heat exchange tubes (113);

wherein the initiating component (201) comprises a rotating blade (603), the rotating blade (603) being arranged in the through hole (602) by a rotating shaft (604) and being connected to the upper transmission part (205) by the rotating shaft (604), wherein the rotating blade (603) is capable of being driven to rotate together with the rotating shaft (604) by the refrigerant vapor flowing in from the intake pipe (102); the transmission part (202) further comprises a cam (601),

the cam (601) is connected to the rotation shaft (604) such that the cam (601) can eccentrically rotate with the rotation of the rotation shaft (604); a receiving part (701) is arranged at the top of the upper transmission part (205),

the cam (601) is rotatably received in the receiving portion (701) such that the eccentric rotation of the cam (601) can drive the upper transmission portion (205) to move up and down.