Scroll assembly and scroll compressor

Abstract

The present application provides a scroll assembly and scroll compressor, the scroll assembly comprising a moving scroll and a fixed scroll, the scroll assembly further having a suction port and a discharge port, the blades of the moving scroll and the blades of the fixed scroll engaging with each other to form a suction cavity, a central compression cavity and an intermediate compression cavity between the moving scroll and the fixed scroll, wherein the end plate of the fixed scroll is provided with modulation holes, the modulation holes comprising multiple groups of modulation holes spaced apart from each other in the direction of the profile line of the fixed scroll, the first group of modulation holes in the multiple groups of modulation holes being arranged at a position closer to the suction port than the other groups of modulation holes, so that at the moment when the suction cavity starts to seal to form the first intermediate compression cavity closest to the suction cavity in the intermediate compression cavity, the first group of modulation holes just starts to be exposed or has been exposed in the first intermediate compression cavity in advance. According to the scroll assembly and scroll compressor of the present application, the energy efficiency is high, the operation is stable and safe, and the noise is low.

Description

TECHNICAL FIELD

[0001] The present invention relates to a scroll compressor, and more particularly, to a scroll compressor having a capacity modulation mechanism. BACKGROUND

[0002] The description in this section merely provides background information related to the present invention and can not constitute prior art.

[0003] It is known that scroll compressors can vary the working capacity of the compressor in various ways according to the needs of the operating conditions, such as varying the compressor speed and / or unloading the scroll assembly. In addition, it is also known that a mechanism for achieving capacity modulation without varying the compressor speed and without unloading the scroll assembly includes components such as a modulation ring, a seal, a control valve, etc., the modulation ring and the seal forming a variable pressure chamber, the control valve controlling the communication of the variable pressure chamber with a higher pressure region inside the compressor or with a lower pressure region inside the compressor, the pressure difference on the upper and lower sides of the modulation ring being able to be controlled so that the modulation ring moves up and down to open or close a modulation hole provided on the fixed scroll and communicating with at least one intermediate compression chamber in the scroll assembly. When the modulation hole is open, the at least one intermediate compression chamber communicates with the lower pressure region inside the compressor through the modulation hole, and the profile of the front part of the scroll assembly hardly participates in compression, thereby achieving the purpose of the compressor working at partial load.

[0004] When the compressor is in a partial load working state, if the modulation hole cannot communicate the compression chamber with the lower pressure region inside the compressor at the first time when the suction chamber of the scroll assembly starts to seal to form a compression chamber, the fluid in the compression chamber will be compressed and then bypass through the modulation hole, thereby causing unnecessary energy loss.

[0005] In addition, for a compressor having a back pressure chamber design, if the modulation hole and the back pressure hole are exposed to the same compression chamber when the compressor is at partial load, the pressure of the back pressure chamber will be reduced and cannot provide effective back pressure, affecting the performance of the compressor.

[0006] Therefore, the present invention aims to provide a compressor having an improved capacity modulation system to improve the performance of the compressor at partial load operating conditions. SUMMARY

[0007] In this section, a general summary of the present invention is provided, rather than a comprehensive disclosure of the full scope or all features of the present invention.

[0008] One of the objectives of the present application is to provide a scroll compressor with an improved capacity regulation system, wherein the arrangement of the modulation holes is designed such that the modulation holes can communicate the compression chamber requiring bypass with a lower pressure area in the compressor at a first time, thereby avoiding the compressed fluid in the compression chamber from being bypassed, thus saving energy and improving the compressor efficiency.

[0009] Another objective of the present application is to provide a scroll compressor with a back pressure design, wherein the arrangement of the modulation holes is designed such that the number (or the flow area) of the modulation holes that can communicate with the back pressure hole is reduced, thereby avoiding the pressure in the back pressure chamber from being excessively reduced at part load, facilitating the sealing fit between the fixed scroll and the orbiting scroll, thus reducing the compressor noise and improving the compressor performance.

[0010] The present application provides a scroll assembly comprising: an orbiting scroll having an orbiting scroll end plate and orbiting scroll vanes formed on the orbiting scroll end plate; and a fixed scroll having a fixed scroll end plate and fixed scroll vanes formed on a first side of the fixed scroll end plate, wherein the scroll assembly has a suction port for drawing working fluid into the scroll assembly and a discharge port for discharging compressed working fluid out of the scroll assembly, the orbiting scroll vanes and the fixed scroll vanes are engaged with each other to form a suction chamber in communication with the suction port, a central compression chamber in communication with the discharge port, and intermediate compression chambers between the suction chamber and the central compression chamber, wherein the fixed scroll end plate is provided with modulation holes via which working fluid inside the scroll assembly can leak to a suction pressure zone outside the scroll assembly to achieve a part load working state of the scroll assembly, and wherein the modulation holes comprise a plurality of groups of modulation holes spaced apart from each other in a profile direction of the fixed scroll, a first group of the plurality of groups of modulation holes is disposed at a position closer to the suction port than other groups of the modulation holes, such that at a time when the suction chamber starts to seal to form a first intermediate compression chamber closest to the suction chamber among the intermediate compression chambers, the first group of the modulation holes just starts to be exposed in the first intermediate compression chamber or has been exposed in the first intermediate compression chamber in advance.

[0011] Optionally, the plurality of groups of modulation holes are configured as two groups of modulation holes comprising a first group of modulation holes and a second group of modulation holes, the first group of modulation holes and the second group of modulation holes are respectively configured to comprise one or more modulation holes, and the first group of modulation holes and the second group of modulation holes are arranged substantially along the profile direction of the fixed scroll.

[0012] Optionally, in the case where the first group of modulation holes and / or the second group of modulation holes are configured to comprise a plurality of modulation holes, the spacing angle between the first group of modulation holes and the second group of modulation holes is greater than the spacing angle between adjacent modulation holes in the same group of the first group of modulation holes and the second group of modulation holes.

[0013] Optionally, the fixed scroll end plate is further provided with a back pressure hole, and the second side of the fixed scroll end plate opposite to the first side is provided with a back pressure cavity, the back pressure cavity is in communication with one of the intermediate compression cavities via the back pressure hole, and the back pressure hole is closer to the exhaust port than the modulation holes.

[0014] Optionally, during operation of the scroll assembly, the second group of modulation holes can be exposed in one intermediate compression cavity together with the back pressure hole, while the first group of modulation holes is not exposed in one intermediate compression cavity.

[0015] Optionally, during operation of the scroll assembly, the first group of modulation holes and the second group of modulation holes can be exposed in the same intermediate compression cavity.

[0016] Optionally, the scroll assembly further comprises a modulation ring provided on the second side of the fixed scroll end plate, in a full load working state of the scroll assembly, the modulation ring seals and covers the modulation holes so as to shut off the leakage of working fluid inside the scroll assembly to the suction pressure area, and in a partial load working state of the scroll assembly, the modulation ring moves away from the modulation holes so as to allow the leakage of working fluid inside the scroll assembly to the suction pressure area.

[0017] Optionally, a variable pressure cavity is formed on the side of the modulation ring close to the fixed scroll end plate, and the back pressure cavity provided on the second side of the fixed scroll end plate opposite to the first side is formed on the side of the modulation ring opposite to the variable pressure cavity, and the variable pressure cavity can be selectively in communication with the back pressure cavity or the suction pressure area.

[0018] Optionally, the variable pressure cavity is selectively in communication with the back pressure cavity or the suction pressure area through a control valve, when the variable pressure cavity is in communication with the suction pressure area, the modulation ring moves to cover the modulation holes, and when the variable pressure cavity is in communication with the back pressure cavity, the modulation ring moves away from the modulation holes.

[0019] Optionally, the modulation holes are arranged on both sides of the exhaust port with respect to the center of the fixed scroll end plate in a substantially radial symmetry, and the modulation holes on at least one side of the exhaust port are configured to include multiple groups of modulation holes.

[0020] Optionally, the total flow area of the first group of modulation holes is greater than the total flow area of the other groups of modulation holes, and / or the number of the first group of modulation holes is greater than the total number of the other groups of modulation holes.

[0021] Optionally, the two compression paths of the scroll assembly on the two radial sides of the exhaust port have substantially the same pressure ratio.

[0022] The present application also provides a scroll compressor comprising the scroll assembly as described above.

[0023] In general, the scroll compressor according to the present application brings at least one of the following advantages: due to the optimized distribution of the modulation holes, the scroll compressor according to the present application can realize the matching of the bypass area of the modulation holes and the compression state of the compression cavity, avoiding the situation that the fluid in the compression cavity is compressed and then bypassed in the state of partial load, and improving the energy efficiency of the compressor; due to the optimized distribution of the modulation holes, the compressor according to the present application can reduce the situation of insufficient pressure in the back pressure cavity caused by the communication between the back pressure hole and the modulation hole, and improve the problems of unstable operation, excessive noise and performance decline of the compressor caused by insufficient back pressure. BRIEF DESCRIPTION OF DRAWINGS

[0024] The foregoing and other features and advantages of the present application will become more apparent from the following detailed description of the application when viewed in conjunction with the accompanying drawings, which are intended to illustrate but not to limit the present application. In the drawings, identical or similar components are denoted with the same reference numerals, and:

[0025] Figure 1 A longitudinal sectional view of a scroll compressor according to a first embodiment of the present application is shown;

[0026] Figure 2 A perspective view of a fixed scroll of a scroll compressor according to the first embodiment of the present application is shown;

[0027] Figure 3 A bottom view of the fixed scroll of the scroll compressor according to the first embodiment of the present application is shown;

[0028] Figure 4a and Figure 4b Cross-sectional views of a scroll assembly of the scroll compressor according to the first embodiment of the present application at different time points are shown, respectively, wherein, Figure 4a a time point when the suction cavity in the scroll assembly starts to be sealed, and only the first group of modulation holes is exposed in the compression cavity, the scroll assembly Figure 4b a time point when the scroll assembly further rotates from Figure 4a the time point shown, and the first group of modulation holes ends the bypass and only the second group of modulation holes is exposed in the compression cavity;

[0029] Figure 5 A bottom view of a fixed scroll of a scroll compressor in a comparative example is shown;

[0030] Figure 6a and Figure 6b Cross-sectional views of a scroll assembly of the scroll compressor in the comparative example at different time points are shown, respectively, wherein, Figure 6a a time point when the suction cavity in the scroll assembly starts to be sealed, Figure 6b a time point when the scroll assembly further rotates from Figure 6a the time point shown, and the modulation holes are exposed in the compression cavity;

[0031] Figure 7 FIG. 9 shows a comparative graph of bypass area of a modulation hole versus pressure in a compression chamber in a scroll compressor according to a first embodiment of the present application and a scroll compressor of a comparative example; and

[0032] Figure 8 FIG. 4 shows a perspective view of a fixed scroll of a scroll compressor according to a second embodiment of the present application. DETAILED DESCRIPTION

[0033] Reference will now be made in detail to the preferred embodiments of the present application, one or more examples of which are illustrated in the drawings. The following description is, therefore, not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the application. Figures 1 to 8 The preferred embodiments of the present application will be described in detail below. Like reference numerals refer to like elements throughout the various views. The following description is merely exemplary in nature and is not intended to limit the present application, its application, or uses.

[0034] Reference will now be made to Figure 1 The basic configuration and principle of a scroll compressor 100 according to a first embodiment of the present application will be described.

[0035] As Figure 1 shown, the scroll compressor (hereinafter, also referred to as a compressor) 100 generally includes a housing 80, a scroll assembly CM disposed in the housing 80, a main bearing housing 50 for supporting the scroll assembly CM, and a motor 70 and a rotating shaft 60 for driving the scroll assembly CM, etc. The housing 80 can be composed of a substantially cylindrical body portion 81, a top cover 82 disposed at one end of the body portion 81, and a bottom cover 83 disposed at the other end of the body portion 81. A partition 84 is disposed between the top cover 82 and the body portion 81 to divide the internal space of the housing 80, wherein the space between the partition 84 and the top cover 82 constitutes a discharge pressure zone HP, and the space between the partition 84, the body portion 81 and the bottom cover 83 constitutes a suction pressure zone LP. A suction port for sucking fluid is provided at one side of the suction pressure zone LP, and a discharge port for discharging compressed fluid is provided at one side of the discharge pressure zone HP.

[0036] The scroll assembly CM includes a fixed scroll 10 and an orbiting scroll 40. The motor 70 is configured to rotate the rotating shaft 60, which in turn drives the orbiting scroll 40 to orbiting motion (i.e., the center axis of the orbiting scroll moves around the center axis of the fixed scroll, but the orbiting scroll does not rotate around its center axis) relative to the fixed scroll 10.

[0037] The fixed scroll 10 can include a fixed scroll end plate 12, fixed scroll blades 14 extending from a first side of the fixed scroll end plate 12, and a fixed scroll hub portion 16 extending from a second side of the fixed scroll end plate 12 opposite the first side. The fixed scroll 10 is further formed with a suction port 15 at a radially outer edge of the fixed scroll end plate 12 for drawing working fluid into the scroll assembly CM, and with a discharge port 123 (see Figure 2 , Figure 3 ) at a center of the fixed scroll end plate 12 for discharging compressed working fluid from the scroll assembly CM. The fixed scroll hub portion 16 is disposed about the discharge port 123 to form a discharge passage in an inner side of the fixed scroll hub portion 16 in communication with the discharge port 123. The orbiting scroll 40 can include an orbiting scroll end plate 42, orbiting scroll blades 44 formed on one side of the orbiting scroll end plate 42. The fixed scroll blades 14 and the orbiting scroll blades 44 are engageable with each other such that a series of fluid pockets are formed between the fixed scroll blades 14 and the orbiting scroll blades 44 when the scroll compressor is in operation. The series of fluid pockets include a suction pocket CS, a central compression pocket CD, and a plurality of intermediate compression pockets, such as a first intermediate compression pocket CI, between the suction pocket CS and the central compression pocket CD (see Figure 4a , Figure 4b ). Among the series of fluid pockets, the suction pocket CS located radially outermost is in communication with the suction port 15 and has a minimum pressure therein, the central compression pocket CD located radially innermost is in communication with the discharge port 123 and has a maximum pressure therein, and the plurality of intermediate compression pockets, such as CI, between the suction pocket CS and the central compression pocket CD have intermediate pressures between the maximum pressure and the minimum pressure. In the embodiment of the present application, the scroll assembly CM is shown to have a symmetrical design, i.e., the two compression paths located radially on both sides of the discharge port 123 have substantially the same pressure ratio, but it is understood by those skilled in the art that the present application is equally applicable to an asymmetrical scroll assembly, i.e., the two compression paths located radially on both sides of the discharge port have different pressure ratios.

[0038] To achieve capacity modulation of the compressor, the scroll assembly CM further includes a modulation ring 20 disposed at the second side of the fixed scroll end plate 12 opposite the first side, the fixed scroll end plate 12 being provided with a modulation aperture 121. The modulation aperture 121 can be disposed to extend through the fixed scroll end plate 12 in an axial direction, thereby forming a bypass passage BP that selectively provides fluid communication between at least one of the intermediate compression pockets of the scroll assembly CM and the suction pressure zone LP. The modulation aperture 121 includes a first open end formed on a surface of the first side of the fixed scroll end plate 12 and a second open end formed on a surface of the second side of the fixed scroll end plate 12. The modulation ring 20 is fitted at an outer peripheral surface of the fixed scroll hub portion 16. As Figure 1As shown, the modulation ring 20 includes a flat portion 22 in surface contact with the top surface of the fixed scroll end plate 12 and a central arched portion 24 spaced apart from the fixed scroll hub 16. The flat portion 22 of the modulation ring 20 is capable of covering the second open end of the sealing modulation hole 121 to achieve the closing of the bypass passage BP. The central arched portion 24 of the modulation ring 20 defines a first annular recess with the fixed scroll hub 16 and a second annular recess with the top surface of the fixed scroll end plate 12. The first and second annular recesses are isolated from each other. A sealed back pressure cavity 26 can be formed in the first annular recess and a sealed variable pressure cavity 28 can be formed in the second annular recess. That is, the back pressure cavity 26 and the variable pressure cavity 28 are respectively provided on two sides of the modulation ring 20. The back pressure cavity 26 can be in communication with at least one intermediate compression cavity of the scroll assembly CM via the back pressure hole 18 provided in the fixed scroll end plate 12 and a back pressure PI is established in the back pressure cavity 26. In the embodiment of the present application, the back pressure hole 18 is preferably one to reduce the limitation on the arrangement of the modulation hole and the possibility of back pressure leakage. Thus, the fixed scroll 10 and the orbiting scroll 40 are kept against each other during the compression of the gas by the scroll assembly CM while providing axial flexibility of the scroll components to ensure safe and reliable operation of the compressor and floating seal.

[0039] The scroll assembly CM further includes a control valve (not shown) capable of selectively fluidly connecting the variable pressure cavity 28 with the back pressure cavity 26 or with the suction pressure zone LP (channels for the connection are not shown). When the control valve controls the variable pressure cavity 28 to be in communication with the suction pressure zone LP, the pressure of the variable pressure cavity 28 is less than that of the back pressure cavity 26, whereby the pressure of the side of the modulation ring 20 provided with the variable pressure cavity 26 (lower side as shown in Figure 1 ) is less than that of the side provided with the back pressure cavity 26 (upper side as shown in Figure 1 ), and under the action of the pressure difference between the two sides, the modulation ring 20 moves axially towards the fixed scroll end plate 12 so that the flat portion 22 of the modulation ring 20 covers the second open end of the sealing modulation hole 121 to close the bypass passage BP. At this time, the working fluid in the intermediate compression cavity of the scroll assembly CM cannot flow out through the bypass passage BP, and the scroll compressor is in full load working condition. When the control valve controls the variable pressure cavity 28 to be in communication with the back pressure cavity 26, the pressures of the variable pressure cavity 28 and the back pressure cavity 26 are equal, but the modulation ring 20 is also subjected to the pressure exerted by the working fluid at the modulation hole to the modulation ring 20, whereby the pressure of the side of the modulation ring 20 provided with the variable pressure cavity 26 (lower side as shown in Figure 1 ) is greater than that of the side provided with the back pressure cavity 26 (upper side as shown in Figure 1When the pressure in the intermediate compression chamber (i.e. the pressure on the upper side of the modulation ring 20) is higher than the pressure in the suction chamber (i.e. the pressure on the lower side of the modulation ring 20), the modulation ring 20 is moved in the axial direction towards the fixed scroll end plate 12, so that the flat portion 22 of the modulation ring 20 is moved away from the second open end of the modulation hole 121, and the bypass passage BP is opened. At this time, the working fluid in the intermediate compression chamber communicating with the modulation hole 121 leaks to the suction pressure area LP outside the scroll assembly CM via the modulation hole 121. At this time, the scroll wrap portion corresponding to the modulation hole 121 and the front portion of the scroll wrap portion thereof hardly participate in compression any more, and the scroll compressor 100 is thus in a partial load working state.

[0040] In the first embodiment of the present application, the back pressure hole 18 is arranged closer to the exhaust port 123 than the modulation hole 121, so as to ensure that the back pressure hole 18 can provide the back pressure to the back pressure chamber 26 in both the full load working state and the partial load working state of the compressor. For example, as shown in Figure 1 、 2 , the modulation hole 121 can be arranged at a position closer to the radial outer side of the fixed scroll end plate 12, and the back pressure hole 18 can be arranged at a position closer to the radial inner side of the fixed scroll end plate 12 and pass through the outer portion of the fixed scroll hub 16 to the back pressure chamber 26.

[0041] As shown in Figure 2 、 3 , the modulation holes 121 are arranged on both sides of the exhaust port 123 in a substantially radial symmetry about the center of the fixed scroll end plate 12. Herein, "substantially radial symmetry" means that the number of the modulation holes on both sides of the exhaust port 123 is basically the same, and the positions of the modulation holes on both sides of the exhaust port 123 are basically radially symmetric about the center of the fixed scroll end plate 12, but the interval between adjacent modulation holes on each side can be different. Among them, the modulation holes 121 on one side of the exhaust port 123 are configured to include a first group of modulation holes 1211 and a second group of modulation holes 1212 arranged along the direction of the scroll wrap of the fixed scroll 10 and spaced apart from each other in the direction of the scroll wrap of the fixed scroll 10, and the modulation holes 121 on the other side of the exhaust port 123 are configured to be a group of modulation holes arranged uniformly along the direction of the scroll wrap of the fixed scroll 10. In particular, the first group of modulation holes 1211 is arranged at a position closer to the suction port 15 than the other modulation holes (the second group of modulation holes 1212), so that the first group of modulation holes 1211 can realize bypass earlier when the compressor is in a partial load working state, thereby achieving the effect of improving energy efficiency, which will be described in detail below.

[0042] The process of realizing bypass of the modulation hole 121 when the compressor is in a partial load working state will be described below in conjunction with Figure 4a and Figure 4b . Figure 4aThis shows the moment when the intake chamber CS in the vortex assembly CM begins to seal, thus forming the first intermediate compression chamber C1 immediately adjacent to the intake chamber CS in the intermediate compression chamber, and the first set of modulation orifices 1211 just begins to be exposed or has already been exposed in advance in the first intermediate compression chamber C1 (in Figure 4a The diagram shows that a portion of the first four modulation holes of the first group 1211 are exposed in the first intermediate compression chamber C1, while the second group 1212 is either blocked by the passive scroll blades 44 or located in a different intermediate compression chamber than the first intermediate compression chamber C1 and is not exposed in the first intermediate compression chamber C1. When the compressor is operating under partial load, the first group of modulation holes 1211, which are exposed in advance in the first intermediate compression chamber C1, allows the working fluid in the first intermediate compression chamber C1 to leak to the suction pressure zone LP in a timely manner. As the moving scroll 40 continues to rotate around the fixed scroll 10, the first group of modulation holes 1211 gradually becomes fully exposed in the first intermediate compression chamber C1, and the second modulation holes 1212 begin to be at least partially exposed in the first intermediate compression chamber C1. That is, the first group of modulation holes 1211 and the second group of modulation holes 1212 can be exposed in the same intermediate compression chamber to provide sufficient bypass area when the compressor is operating under partial load. As the moving scroll 40 continues to rotate around the fixed scroll 10, the first group of modulation holes 1211 gradually becomes blocked by the passive scroll blades 44, and then reaches... Figure 4b The time shown. At Figure 4b At the indicated moment, the passive vortex blades 44 of the first set of modulation holes 1211 are completely blocked or the first set of modulation holes 1211 are at least partially exposed in a different chamber (e.g., intake chamber CS) than the intermediate compression chamber exposed by the second set of modulation holes 1212, while the second set of modulation holes 1212 and the back pressure hole 18 are exposed in the same intermediate compression chamber, which is the first intermediate compression chamber C1, or it can be another intermediate compression chamber different from the first intermediate compression chamber C1. At this time, the second set of modulation holes 1212 still allows the working fluid in the intermediate compression chamber to leak to the intake pressure zone LP.

[0043] Preferably, during the entire operation of the vortex assembly, the first set of modulation holes 1211 is never exposed in the same intermediate compression chamber as the back pressure hole 18, so as to avoid insufficient back pressure caused by leakage of the working fluid in the back pressure chamber 26 through the first set of modulation holes 1211 under partial load operation.

[0044] The following will combine Figure 5 , Figure 6a , Figure 6bThe structure of the fixed scroll of the scroll compressor in the comparative example is described, and the effect of the first embodiment of the present application is described by comparing the first embodiment of the present application with the comparative example. The structure and working principle of the scroll compressor in the comparative example are basically the same as those of the scroll compressor in the first embodiment of the present application, and thus are not described here again.

[0045] The scroll compressor in the comparative example includes a scroll assembly CMa including a fixed scroll 10a and an orbiting scroll 40. As shown, the fixed scroll 10a includes a fixed scroll end plate 12 and fixed scroll blades 14 extending from a first side of the fixed scroll end plate 12, similarly to the first embodiment of the present application. The fixed scroll 10a further includes a suction port 15 for sucking working fluid into the scroll assembly CMa and a discharge port 123 for discharging compressed working fluid from the scroll assembly. The fixed scroll end plate 12 is further provided with modulation holes 121a which can be arranged to extend through the fixed scroll end plate 12 in an axial direction, thereby forming a bypass passage BP selectively providing fluid communication between at least one intermediate compression chamber of the scroll assembly CMa and the suction pressure zone LP. The scroll assembly CMa further includes a modulation ring 20 arranged at a second side of the fixed scroll end plate 12, which, in a full load working state of the scroll assembly, sealingly covers the modulation holes to shut off the leakage of working fluid inside the scroll assembly to the suction pressure zone LP, and which, in a partial load working state of the scroll assembly, moves away from the modulation holes 121a to allow the leakage of working fluid inside the scroll assembly to the suction pressure zone LP. Figure 5 The modulation holes 121a are arranged substantially radially symmetrically about the center of the fixed scroll end plate 12 on both sides of the discharge port 123. Unlike the first embodiment of the present application, the modulation holes 121a on each side of the discharge port 123 are configured as a group of modulation holes arranged uniformly along the profile direction of the fixed scroll 10a. That is, for the modulation holes 121a on each side of the discharge port 123, the interval distance between adjacent modulation holes in the group of modulation holes on the side is substantially equal.

[0046]

[0047] As shown, at the moment when the suction chamber CS in the scroll assembly CMa starts to seal to form a first intermediate compression chamber CI which is immediately adjacent to the suction chamber CS in the intermediate compression chambers, the modulation holes 121a on each side of the discharge port 123 are either blocked by the orbiting scroll blades 44 or located in intermediate compression chambers other than the first intermediate compression chamber CI and thus are not exposed in the first intermediate compression chamber CI, and thus, in the partial load working state of the compressor, the working fluid in the first intermediate compression chamber CI is not allowed to leak to the suction pressure zone LP through the modulation holes 121a on each side of the discharge port 123. Figure 6a Figure 6a ​The bypass has not started at the time shown. As the orbiting scroll 40 continues to rotate around the fixed scroll 10, the modulation hole 121a is gradually exposed in the first intermediate compression chamber C1, and the working fluid in the first intermediate compression chamber C1 leaks to the suction pressure area via the modulation hole 121a, and then reaches Figure 6b The time shown. In Figure 6b The time shown, the modulation hole 121a on the exhaust port 123 side is exposed in the same intermediate compression chamber as the back pressure hole 18, which is the first intermediate compression chamber C1, or other intermediate compression chamber different from the first intermediate compression chamber C1.

[0048] Because the arrangement of the modulation hole on the fixed scroll in the first embodiment of the application is different from that in the comparative example, the bypass process formed by the modulation hole when the compressor is in a partial load working state is also different, thus different effects are produced. Figure 7 The curves of the flow area of the modulation hole and the pressure in the compression chamber changing with the suction sealing angle are shown in the first embodiment of the application and the comparative example, wherein the thick solid line and the thin solid line respectively represent the change curves of the flow area of the modulation hole in the first embodiment of the application and in the comparative example, the thick dashed line and the thin dashed line respectively represent the change curves of the pressure in the compression chamber in the first embodiment of the application and in the comparative example, and the suction sealing angle of 0° is defined as the angle position corresponding to the starting sealing point of the suction chamber CS of the scroll assembly at the time when the suction chamber CS just starts to seal to form the first intermediate compression chamber, which gradually moves with the orbiting rotation of the orbiting scroll relative to the fixed scroll, and ends the compression of the first intermediate compression chamber when it moves to 360°.

[0049] As Figure 7 As shown in the comparative example, at the time when the suction chamber CS of the scroll assembly CMa just starts to seal to form the first intermediate compression chamber C1, the modulation hole 121a has not been exposed in the first intermediate compression chamber C1, i.e. the flow area of the modulation hole is equal to 0, and even when the suction chamber CS of the scroll assembly has been sealed, the modulation hole 121a has not started to be exposed in the first intermediate compression chamber. Because the modulation hole cannot be timely exposed in the first intermediate compression chamber, the first intermediate compression chamber cannot be timely communicated with the suction pressure area, and the first stage compression cannot be started (corresponding to the time when the suction sealing angle is 0° in the comparative example). Figure 7the first intermediate compression chamber C1, the working fluid that has undergone more compression is discharged to the outside of the scroll assembly via the modulation holes 121a, and the pressure in the first intermediate compression chamber C1 gradually decreases. Those skilled in the art can understand that this process of first compressing the working fluid and then bypassing the compressed working fluid results in waste of work done by the scroll assembly, and thus the energy efficiency of the compressor is relatively low. In contrast, in the first embodiment of the present application, at the moment when the suction chamber CS of the scroll assembly CM is just sealed to form the first intermediate compression chamber C1, the modulation holes 121 (the first group of modulation holes 1211) have been partially exposed in the first intermediate compression chamber C1, i.e., the flow area of the modulation holes at this moment is greater than 0. Since the modulation holes 121 are exposed in the first intermediate compression chamber C1 in advance, the modulation holes 121 can timely communicate the first intermediate compression chamber C1 with the suction pressure area LP, so that the working fluid in the first intermediate compression chamber C1 can be discharged to the suction pressure area LP via the modulation holes 121 in the startup phase (corresponding to the phase of the suction sealing angle of about 0°-80°), and the working fluid in the first intermediate compression chamber C1 does not undergo compression or only undergos little compression in the startup phase, so that the pressure in the compression chamber (the first intermediate compression chamber C1) does not have a significant fluctuation in the startup phase. Those skilled in the art can understand that, in the first embodiment of the present application, since the working fluid is not discharged via the modulation holes after undergoing more compression in the startup phase, there is no energy waste due to the compression in the startup phase, thereby improving the energy efficiency of the compressor. Figure 7 the first intermediate compression chamber C1, the working fluid that has undergone more compression is discharged to the outside of the scroll assembly via the modulation holes 121a, and the pressure in the first intermediate compression chamber C1 gradually decreases. Those skilled in the art can understand that this process of first compressing the working fluid and then bypassing the compressed working fluid results in waste of work done by the scroll assembly, and thus the energy efficiency of the compressor is relatively low. In contrast, in the first embodiment of the present application, at the moment when the suction chamber CS of the scroll assembly CM is just sealed to form the first intermediate compression chamber C1, the modulation holes 121 (the first group of modulation holes 1211) have been partially exposed in the first intermediate compression chamber C1, i.e., the flow area of the modulation holes at this moment is greater than 0. Since the modulation holes 121 are exposed in the first intermediate compression chamber C1 in advance, the modulation holes 121 can timely communicate the first intermediate compression chamber C1 with the suction pressure area LP, so that the working fluid in the first intermediate compression chamber C1 can be discharged to the suction pressure area LP via the modulation holes 121 in the startup phase (corresponding to the phase of the suction sealing angle of about 0°-80°), and the working fluid in the first intermediate compression chamber C1 does not undergo compression or only undergos little compression in the startup phase, so that the pressure in the compression chamber (the first intermediate compression chamber C1) does not have a significant fluctuation in the startup phase. Those skilled in the art can understand that, in the first embodiment of the present application, since the working fluid is not discharged via the modulation holes after undergoing more compression in the startup phase, there is no energy waste due to the compression in the startup phase, thereby improving the energy efficiency of the compressor.

[0050] Then, in both the first embodiment of the application and the comparative example, as the orbiting rotation of the orbiting scroll relative to the fixed scroll progresses, more and more of the modulation holes are exposed in the first intermediate compression chamber, i.e. the flow area of the modulation holes further increases, until all of the modulation holes are exposed in the first intermediate compression chamber, the flow area of the modulation holes reaches a maximum, at which point the pressure in the first intermediate compression chamber is substantially equal to the pressure of the suction pressure zone. Then, when the orbiting rotation of the orbiting scroll relative to the fixed scroll progresses to an angle of about 250 degrees of the suction sealing angle, some of the modulation holes 121 (e.g. the first group of modulation holes 1211) on the side of the exhaust port 123 in the first embodiment of the application are covered by the orbiting scroll vanes 44 or are located in other chambers (e.g. the suction chamber CS) other than the first intermediate compression chamber CI, ending the bypass of the first intermediate compression chamber CI, the number of modulation holes (or the flow area) for communicating the first intermediate compression chamber CI and the suction pressure zone LP is reduced, the working fluid in the first intermediate compression chamber CI starts to be compressed as it cannot be discharged in time to the outside of the scroll assembly, the pressure in the first intermediate compression chamber CI gradually rises, and after the orbiting rotation of the orbiting scroll relative to the fixed scroll progresses to an angle of 360 degrees of the suction sealing angle, the working fluid enters the next stage of compression chamber for compression. In contrast, in the comparative example, when the orbiting rotation of the orbiting scroll relative to the fixed scroll progresses to an angle of about 250 degrees of the suction sealing angle, the modulation holes 121a have not yet been covered by the orbiting scroll vanes or located in other chambers other than the first intermediate compression chamber, but are still all exposed in the first intermediate compression chamber CI, so the pressure in the first intermediate compression chamber CI remains substantially equal to the pressure of the suction pressure zone. At this point, if the back pressure hole 18 is also located in the first compression chamber, it will cause the pressure in the back pressure chamber 26 to leak to the first intermediate compression chamber CI and to the outside of the scroll assembly via the back pressure hole 18, resulting in insufficient back pressure, ineffective sealing between the fixed scroll and the orbiting scroll, leakage, and repeated compression of the working fluid in the compression chamber, which results in an increase in exhaust temperature, a decrease in compressor performance, and noise.

[0051] That is, in the first stage compression termination phase (corresponding to Figure 7In the first embodiment of the present application, the modulation holes 121 on the side of the exhaust port 123, including the first group of modulation holes 1211 and the second group of modulation holes 1212, end the bypass earlier than the modulation holes 121a in the comparative example, so that the pressure in the first intermediate compression chamber C1 starts to rise earlier, which is important for maintaining the pressure in the back pressure chamber stable. For example, if the back pressure holes and the modulation holes can be exposed to the first intermediate compression chamber together, at the end of the first stage compression, due to the reduced number of modulation holes for connecting the first intermediate compression chamber and the suction pressure zone in the first embodiment of the present application (only the second group of modulation holes is connected to the suction pressure zone, and the first group of modulation holes is not connected to the suction pressure zone), the pressure in the first intermediate compression chamber rises, thereby ensuring that the working fluid in the back pressure chamber does not leak too much into the first intermediate compression chamber through the back pressure holes, and the pressure in the back pressure chamber does not decrease too much, thereby providing reliable back pressure for the scroll assembly.

[0052] In the first embodiment of the present application, the first group of modulation holes and the second group of modulation holes are respectively configured as one or more. Preferably, the number of the first group of modulation holes is greater than the total number of the other group of modulation holes (the second group of modulation holes in the first embodiment of the present application), or preferably, the total flow area of the first group of modulation holes is greater than the total flow area of the other group of modulation holes (the second group of modulation holes in the first embodiment of the present application), thereby better avoiding pressure fluctuations in the starting stage and better reducing pressure leakage of the back pressure chamber. For example, as shown in FIG. 1, the first group of modulation holes 1211 is configured as 5, and the second group of modulation holes 1212 is configured as 2. However, those skilled in the art can understand that the number of the first group of modulation holes can also be equal to or less than the number of the other group of modulation holes. Figure 2 、 3 As shown in FIG. 1, the first group of modulation holes 1211 is configured as 5, and the second group of modulation holes 1212 is configured as 2. However, those skilled in the art can understand that the number of the first group of modulation holes can also be equal to or less than the number of the other group of modulation holes.

[0053] The first group of modulation holes 1211 and the second group of modulation holes 1212 are spaced apart by a first angle (i.e., the angle between the modulation hole in the first group of modulation holes 1211 closest to the second group of modulation holes 1212 and the modulation hole in the second group of modulation holes 1212 closest to the first group of modulation holes 1211), and adjacent modulation holes in the first group of modulation holes 1211 and adjacent modulation holes in the second group of modulation holes 1212 are spaced apart by substantially the same second angle, and the first angle is greater than the second angle. Preferably, the first angle is configured to be 2 to 10 times the second angle, and more preferably, the first angle is configured to be more than 5 times the second angle. In this way, not only can the early exposure of the first group of modulation holes 1211 in the first intermediate compression chamber be ensured to prevent pressure fluctuations in the starting stage, but also the adjustment of the capacity of the compressor can be achieved by adjusting the position of the second group of modulation holes 1212. For example, assuming that the first group of modulation holes 1211 is configured as 5, and the second group of modulation holes 1212 is configured as 2, as shown in FIG. 1, if the position of the second group of modulation holes 1212 is adjusted to 1, the capacity of the compressor will be reduced by 50%, and if the position of the second group of modulation holes 1212 is adjusted to 3, the capacity of the compressor will be increased by 50%. Figures 1 to 4bIn the first embodiment of the present application shown, the scroll compressor 100 operates at 80% capacity in the part-load operating condition. If the second set of modulation holes is arranged at a position closer to the discharge port 123 along the direction of the profile of the fixed scroll 10 than the second set of modulation holes 1212 in the first embodiment, the compressor will operate at less than 80% capacity in the part-load operating condition.

[0054] The structure of the fixed scroll of the scroll compressor in the second embodiment of the present application will be described below. Figure 8 The structure and operating principle of the scroll compressor in the second embodiment of the present application are basically the same as those of the scroll compressor in the first embodiment of the present application, and thus will not be described again here.

[0055] The scroll compressor in the second embodiment of the present application comprises a scroll assembly including a fixed scroll 10b and an orbiting scroll 40. As shown, Figure 8 The fixed scroll 10b includes a fixed scroll end plate 12 and fixed scroll blades 14 extending from a first side of the fixed scroll end plate 12, similar to the first embodiment of the present application. The fixed scroll 10b further includes a suction port 15 for drawing working fluid into the scroll assembly and a discharge port 123 for discharging compressed working fluid from the scroll assembly. The fixed scroll end plate 12 is further provided with modulation holes 121b which can be arranged to extend through the fixed scroll end plate 12 in the axial direction, thereby forming a bypass passage BP selectively providing fluid communication between at least one intermediate compression chamber of the scroll assembly and the suction pressure zone LP. The scroll assembly further includes a modulation ring 20 arranged at a second side of the fixed scroll end plate 12. In the full-load operating condition of the scroll assembly, the modulation ring 20 sealingly covers the modulation holes to shut off the leakage of working fluid inside the scroll assembly to the suction pressure zone LP. In the part-load operating condition of the scroll assembly, the modulation ring 20 moves away from the modulation holes 121b to allow the leakage of working fluid inside the scroll assembly to the suction pressure zone.

[0056] The modulation holes 121b are arranged substantially radially symmetrically about the center of the fixed scroll end plate 12 on both sides of the exhaust port 123. Unlike the first embodiment of the present application, the modulation holes 121b on each side of the exhaust port 123 are configured to include a first group of modulation holes 1211b and a second group of modulation holes 1212b arranged along the profile direction of the fixed scroll 10b and spaced apart from each other in the profile direction of the fixed scroll 10b. The first group of modulation holes 1211b is disposed at a position closer to the suction port 15 than the other modulation holes (the second group of modulation holes 1212b), so that at the time when the suction cavity starts to be sealed to form the first intermediate compression cavity, the first group of modulation holes 1211b on both sides of the exhaust port 123 can just start to be exposed or have been exposed in advance in the respective corresponding first intermediate compression cavities. In some examples, the modulation holes on both sides of the exhaust port 123 are identical in terms of the number of groups of modulation holes, the number of modulation holes, the size, the spacing angle between groups of modulation holes, the spacing angle between adjacent modulation holes in the same group of modulation holes, and the like. That is, the modulation holes 121b can be arranged completely radially symmetrically about the center of the fixed scroll end plate 12 on both sides of the exhaust port 123.

[0057] The compressor according to the second embodiment of the present application can obtain the same effects of improving energy efficiency, maintaining stable back pressure cavity pressure, and reducing noise as the compressor according to the first embodiment of the present application, and in addition, since the modulation holes 121b are arranged more radially symmetrically about the center of the fixed scroll end plate 12 on both sides of the exhaust port 123 in the second embodiment, the pressure on both sides of the exhaust port 123 of the scroll assembly CM is more balanced, so that the operation of the compressor is more stable.

[0058] Experiments show that, under the working condition of an evaporation temperature of 50F and a condensation temperature of 100F, when the compressor is in a partial load working state, the compressor according to the first embodiment of the present application has a capacity increase of 2.3% and a total energy efficiency increase of 1.1% compared with the compressor according to the comparative example; the compressor according to the second embodiment of the present application has a capacity increase of 1.2% compared with the compressor according to the comparative example. Under the working condition of an evaporation temperature of 45F and a condensation temperature of 140F, when the compressor is in a partial load working state, the compressor according to the first embodiment of the present application has an exhaust temperature decrease of 19F compared with the compressor according to the comparative example; the compressor according to the second embodiment of the present application has an exhaust temperature decrease of 15F compared with the compressor according to the comparative example.

[0059] Those skilled in the art can understand that, although Figure 1In the illustrated embodiment, only the modulation holes 121 extending through the fixed scroll end plate 12 in the axial direction are shown, but alternatively, the modulation holes 121 can also include inclined holes (i.e., holes extending obliquely with respect to the axis of the fixed scroll 10), a combination of axial holes and lateral holes (i.e., holes extending perpendicular to the axis of the fixed scroll 10) provided in the fixed scroll end plate 12 and in fluid communication with each other, or a combination of axial holes and inclined holes (not shown), as long as the modulation holes 121 are capable of communicating the predetermined intermediate compression chamber with the suction pressure region in the partial load operating state of the compressor. In addition, although the modulation holes on one or both sides of the exhaust port 123 in the radial direction are described in the embodiments of the present application as including two sets of modulation holes (the first set of modulation holes and the second set of modulation holes) spaced apart in the profile direction of the fixed scroll, alternatively, for the one-sided modulation holes, the modulation holes can include three or more sets of modulation holes spaced apart in the profile direction of the fixed scroll.

[0060] The scroll assembly and scroll compressor according to the preferred embodiments of the present application are described above in conjunction with the specific embodiments. It is understood that the above description is merely exemplary but not restrictive and that various modifications and alterations can be conceived by those skilled in the art with reference to the above description without departing from the scope of the present application. Such modifications and alterations are also included in the scope of the present application.

Claims

1. A scroll assembly (CM) comprising: a moving scroll (40) having a moving scroll end plate (42) and moving scroll blades (44) formed on the moving scroll end plate; and a fixed scroll (10) having a fixed scroll end plate (12) and fixed scroll blades (14) formed on a first side of the fixed scroll end plate, wherein the scroll assembly has a suction port (15) for drawing a working fluid into the scroll assembly and a discharge port (123) for discharging a compressed working fluid out of the scroll assembly, the moving scroll blades and the fixed scroll blades engage with each other to form a suction cavity (CS) in communication with the suction port, a central compression cavity (CD) in communication with the discharge port, and intermediate compression cavities between the suction cavity and the central compression cavity, wherein the fixed scroll end plate is provided with modulation holes (121, 121b) via which a working fluid inside the scroll assembly can leak to a suction pressure zone outside the scroll assembly to achieve a partial load working state of the scroll assembly, characterized in that the modulation holes comprise a plurality of groups of modulation holes spaced apart from each other in a profile direction of the fixed scroll, a first group of modulation holes (1211, 1211b) of the plurality of groups of modulation holes is disposed at a position closer to the suction port than other groups of modulation holes, such that at a moment when the suction cavity starts to seal to form a first intermediate compression cavity (C1) immediately adjacent to the suction cavity in the intermediate compression cavities, the first group of modulation holes just starts to be exposed in the first intermediate compression cavity or has been exposed in the first intermediate compression cavity in advance. the plurality of groups of modulation holes are configured as two groups of modulation holes comprising the first group of modulation holes (1211, 1211b) and a second group of modulation holes (1212, 1212b), the first group of modulation holes and the second group of modulation holes are respectively configured to comprise one or more modulation holes, and the first group of modulation holes and the second group of modulation holes are arranged substantially along the profile direction of the fixed scroll.

2. The scroll assembly (CM) of claim 1, wherein, in the case that the first group of modulation holes and / or the second group of modulation holes are configured to comprise a plurality of modulation holes, a spacing angle between the first group of modulation holes and the second group of modulation holes is greater than a spacing angle between adjacent modulation holes in the same group of modulation holes of the first group of modulation holes and the second group of modulation holes.

3. The scroll assembly (CM) of claim 2, wherein, the fixed scroll end plate is further provided with a back pressure hole (18), a second side of the fixed scroll end plate opposite to the first side is provided with a back pressure cavity (26) in communication with one of the intermediate compression cavities via the back pressure hole, and the back pressure hole is closer to the discharge port than the modulation holes.

4. The scroll assembly (CM) of claim 2, wherein, during operation of the scroll assembly, the second group of modulation holes (1212, 1212b) can be exposed in the one intermediate compression cavity together with the back pressure hole, while the first group of modulation holes is not exposed in the one intermediate compression cavity.

5. The scroll assembly (CM) of claim 4, wherein, during operation of the scroll assembly, the first group of modulation holes and the second group of modulation holes can be exposed in the same intermediate compression cavity.

6. The scroll assembly (CM) according to any one of claims 2 to 5, wherein, ​ 7. The scroll assembly (CM) according to any one of claims 1 to 5, wherein, The scroll assembly further includes a modulation ring (20) disposed on a second side of the fixed scroll end plate opposite the first side, the modulation ring sealingly covering the modulation aperture to shut off leakage of working fluid from an interior of the scroll assembly to the suction pressure zone in a full load operating condition of the scroll assembly, the modulation ring moving away from the modulation aperture to allow leakage of working fluid from the interior of the scroll assembly to the suction pressure zone in the partial load operating condition of the scroll assembly.

8. The scroll assembly (CM) of claim 7, wherein, A variable pressure chamber (28) is formed on a side of the modulation ring proximate the fixed scroll end plate, a back pressure chamber (26) disposed on a second side of the fixed scroll end plate opposite the first side is formed on a side of the modulation ring opposite the variable pressure chamber, the variable pressure chamber being selectively communicable with the back pressure chamber or the suction pressure zone.

9. The scroll assembly (CM) of claim 8, wherein, The variable pressure chamber is selectively communicable with the back pressure chamber or the suction pressure zone via a control valve, the modulation ring moving to cover the modulation aperture when the variable pressure chamber is communicable with the suction pressure zone and moving away from the modulation aperture when the variable pressure chamber is communicable with the back pressure chamber.

10. The scroll assembly (CM) according to any one of claims 1 to 5, wherein, The modulation apertures are arranged in generally radial symmetry about a center of the fixed scroll end plate on either side of the exhaust port, the modulation apertures on at least one side of the exhaust port being configured to include the plurality of sets of modulation apertures.

11. The scroll assembly (CM) according to any one of claims 1 to 5, wherein, The first set of modulation apertures has a total flow area greater than a total flow area of the other sets of modulation apertures and / or the first set of modulation apertures has a number greater than a total number of the other sets of modulation apertures.

12. The scroll assembly (CM) according to any one of claims 1 to 5, wherein, The two compression paths of the scroll assembly on either side of the exhaust port have generally the same pressure ratio.

13. A scroll compressor (100) characterized by, The scroll compressor includes the scroll assembly (CM) of any of claims 1-12.

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