A reflux device and a centrifugal compressor comprising the same.

Abstract

This invention provides a reflux circulator comprising at least one row of blades mounted between two cover plates, each row of blades comprising multiple blades, wherein multiple blades in at least one row have not identical mounting angles. By setting different blade mounting angles, the reflux circulator of this invention improves the flow characteristics of the reflux circulator under partial load, thus broadening the operating range of the centrifugal compressor.

Description

Technical Field

[0001] This invention relates to the field of compressors, and more specifically, to a reflux device and a centrifugal compressor comprising the same. Background Technology

[0002] As a major energy-consuming device, the operating efficiency of centrifugal compressors is particularly important for energy conservation. Compared with the operating efficiency at the rated operating point, the operating efficiency at partial load is even more important, because the equipment is often selected based on the worst operating conditions to leave a certain margin. Centrifugal compressors mostly operate at partial load.

[0003] The reflux valve in a centrifugal compressor is mainly used to guide the first-stage outlet gas so that it can smoothly enter the second stage, while simultaneously de-swirls the strong rotating airflow at the outlet of the previous stage impeller.

[0004] Ordinary return flow devices use a single-row blade cascade. The blade inlet installation angle is consistent with the first-stage airflow outlet flow angle at the design point. After being guided by the return flow device blades, the outlet airflow angle can be maintained at around 90°. Figure 1 As shown.

[0005] Chinese patent application number CN201410386372.2 discloses a reflux device for a centrifugal compressor and a centrifugal compressor having the same. The reflux device uses two rows of blades. Compared with a single row of blades, the development of the boundary layer is restricted and disrupted when entering the second row of blades, thereby improving the airflow separation phenomenon, enhancing the deswirl effect, and thus improving the efficiency of the reflux device.

[0006] In existing centrifugal compressor reflux units, whether single-row or double-row, the inlet and outlet installation angles of all blades are designed to match the flow angles under rated operating conditions. However, centrifugal compressors operate under partial load most of the time, at which point the gas flow angle differs from that under rated operating conditions. At the reflux unit inlet, the airflow forms a certain angle of attack with the blades, causing impact losses. In severe cases, this can lead to boundary layer separation and induce surge. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a reflux device that can improve the flow field of the working fluid under partial load and a centrifugal compressor containing the reflux device.

[0008] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0009] The present invention provides a reflux device including at least one row of blades mounted between two cover plates, each row of blades including multiple blades, wherein multiple blades in at least one row have not exactly the same mounting angle.

[0010] The beneficial effects of this invention are: by setting different blade installation angles, the flow characteristics of the return flower under partial load are improved, thereby expanding the operating range of the centrifugal compressor.

[0011] Furthermore, the mounting angle includes an inlet mounting angle and / or an outlet mounting angle.

[0012] Furthermore, the installation angle includes the inlet installation angle. All blades in each row of the blade cascade are located on a circumference. The multiple blades of at least one row of the blade cascade are divided into N groups. The blades in each group have the same inlet installation angle, and the blades in different groups have different inlet installation angles. The inlet installation angles of the N groups of blades correspond one-to-one with the airflow angles of the return flow inlet under N different loads. The proportion of the number of blades in each of the N groups of blades is consistent with the weighting coefficients under the N different loads.

[0013] The beneficial effects of the above-mentioned further scheme are: by setting different blade inlet installation angles and keeping their number proportion consistent with the weighting coefficient during partial load operation, the flow characteristics of the return flower under partial load are improved, and the operating range of the centrifugal compressor is broadened; and the situation where the airflow at the inlet forms a certain angle of attack with the blades, thereby causing impact loss, and in severe cases leading to boundary layer separation, and thus inducing surge effect, is avoided.

[0014] Furthermore, the multiple blades are divided into four groups: the first blade group, the second blade group, the third blade group, and the fourth blade group. The inlet installation angles of the blades in the first blade group, the second blade group, the third blade group, and the fourth blade group correspond to the airflow angles at the inlet of the return valve under 100%, 75%, 50%, and 25% loads, respectively. The ratio of the number of blades in the first blade group, the second blade group, the third blade group, and the fourth blade group is consistent with the weighting coefficients under 100%, 75%, 50%, and 25% loads.

[0015] The beneficial effect of the above-mentioned further scheme is that it provides an optimal technical solution for improving the flow characteristics of the return flower under partial load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Chillers for Commercial and Similar Applications", the weighting coefficients for 100%, 75%, 50%, and 25% loads are 2.3%, 41.5%, 46.1%, and 10.1%, respectively. That is, the ratio of the number of blades in the first, second, third, and fourth blade groups is 2.3%:41.5%:46.1%:10.1%. Furthermore, if the number of blades in a corresponding ratio is less than 1, it is increased to 1; otherwise, the nearest integer is used.

[0016] Furthermore, the installation angle includes the outlet installation angle. All blades in each row of the blade cascade are located on a circumference. Multiple blades in at least one row of the blade cascade are divided into M groups. The blades in each group have the same outlet installation angle. The blades in different groups have different outlet installation angles. The installation angles of the M groups of blades correspond one-to-one with the airflow angles of the return outlet under M different loads. The proportion of the number of blades in each group of the M groups of blades is consistent with the weighting coefficients under the M different loads.

[0017] The beneficial effects of the above-mentioned further scheme are: by setting different blade outlet installation angles and keeping their number proportion consistent with the weighting coefficient during partial load operation, the flow characteristics of the return flower under partial load are improved, and the operating range of the centrifugal compressor is broadened; and the situation where the airflow at the outlet forms a certain angle of attack with the blades, thereby causing impact loss, and in severe cases leading to boundary layer separation, and thus inducing surge effect, is avoided.

[0018] Furthermore, the multiple blades are divided into four groups: the first blade group, the second blade group, the third blade group, and the fourth blade group. The outlet installation angles of the blades in the first blade group, the second blade group, the third blade group, and the fourth blade group correspond to the airflow angles at the outlet of the return valve under 100%, 75%, 50%, and 25% loads, respectively. The ratio of the number of blades in the first blade group, the second blade group, the third blade group, and the fourth blade group is consistent with the weighting coefficients under 100%, 75%, 50%, and 25% loads.

[0019] The beneficial effect of the above-mentioned further scheme is that it provides an optimal technical solution for improving the flow characteristics of the return flower under partial load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Chillers for Commercial and Similar Applications", the weighting coefficients for 100%, 75%, 50%, and 25% loads are 2.3%, 41.5%, 46.1%, and 10.1%, respectively. That is, the ratio of the number of blades in the first, second, third, and fourth blade groups is 2.3%:41.5%:46.1%:10.1%. Furthermore, if the number of blades in a corresponding ratio is less than 1, it is increased to 1; otherwise, the nearest integer is used.

[0020] Furthermore, the blade cascade consists of two rows, namely a first row of blade cascades and a second row of blade cascades, which are located on the inner and outer circumferential rings;

[0021] That is, the multiple blades in the first row of blades have not exactly the same mounting angle, while the multiple blades in the second row of blades have the same mounting angle; or, the multiple blades in the first row of blades have the same mounting angle, while the multiple blades in the second row of blades have not exactly the same mounting angle; or, the multiple blades in the first row of blades and the multiple blades in the second row of blades both have different mounting angles.

[0022] The beneficial effect of the above-mentioned further scheme is that it provides a rule for setting the installation angle when there are two rows of blades. That is to say, when the return flow has two rows of blades, whether only the inlet installation angle and / or outlet installation angle of the first row of blades is changed as described above, or only the inlet installation angle and / or outlet installation angle of the second row of blades is changed as described above, or both the inlet installation angle and / or outlet installation angle of the first row of blades and the second row of blades are changed as described above, the effect of improving the flow characteristics of the return flow under partial load can be achieved.

[0023] Furthermore, the number of blades in the first row of leaf cascades is the same as the number of blades in the second row of leaf cascades.

[0024] Furthermore, the multiple blades of the first row of leaf cascades and the multiple blades of the second row of leaf cascades are arranged in a staggered manner.

[0025] The present invention also relates to a centrifugal compressor, including the reflux device as described above.

[0026] The blade inlet installation angle mentioned above refers to the angle between the tangent of the blade rib line at the inlet and its corresponding circumferential tangent. Figure 1 The included angle A1 is shown; the blade exit installation angle refers to the angle between the tangent of the blade rib line at the exit and its corresponding circumferential tangent, as shown in Figure A1. Figure 1 As shown in the included angle A2. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the blade cascade structure of the reflux device of the present invention;

[0028] Figure 2 This is a schematic diagram of a grouping structure of the reflux cascade of the present invention.

[0029] Explanation of reference numerals in the attached figures

[0030] 1. Blade, 11. First blade group, 12. Second blade group, 13. Third blade group, 14. Fourth blade group, A1. Inlet mounting angle, A2. Outlet mounting angle. Detailed Implementation

[0031] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0032] In the following embodiments, the blade inlet installation angle refers to the angle between the tangent of the blade rib line at the inlet and its corresponding circumferential tangent, such as... Figure 1 The included angle A1 is shown; the blade exit installation angle refers to the angle between the tangent of the blade rib line at the exit and its corresponding circumferential tangent, as shown in Figure A1. Figure 1 As shown in the included angle A2.

[0033] like Figure 2 As shown, Figure 2 This is a schematic diagram of a grouping structure of the blade cascade of the reflux device of the present invention. Different filling patterns in the figure represent different blade groups. Figure 2 The paper presents a staggered distribution of the blades in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14. The blade groups in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 can also be distributed sequentially or randomly.

[0034] Example 1

[0035] The present invention provides a reflux device, comprising a row of blades mounted between two cover plates, each row of blades comprising multiple blades 1, the multiple blades 1 having not exactly the same inlet mounting angle.

[0036] As a further embodiment, the multiple blades are located on a circumference and divided into N groups. The blades 1 in each group have the same inlet installation angle, and the blades 1 in different groups have different inlet installation angles. The inlet installation angles of the N groups of blades correspond one-to-one with the airflow angles of the return flow inlet under N different loads. The proportion of the number of blades 1 in each of the N groups of blades is consistent with the proportion of the weighting coefficients under the N different loads.

[0037] As a further embodiment, the multiple blades 1 are divided into 4 groups, namely the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14. The inlet installation angle of the blades 1 in the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14 corresponds to the airflow angle at the inlet of the return valve under 100%, 75%, 50% and 25% load, respectively. The ratio of the number of blades in the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14 is consistent with the weighting coefficients under 100%, 75%, 50% and 25% load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Chiller Heat Pump Units for Commercial and Similar Applications", the weighting coefficients for 100%, 75%, 50%, and 25% loads are 2.3%, 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of blades in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 is 2.3%:41.5%:46.1%:10.1%. Furthermore, if the number of blades in a corresponding ratio is less than 1, it is increased to 1; otherwise, the nearest integer is used. For example, if the total number of blades in each blade row is 19, the first group has 1 blade, the second group has 8 blades, the third group has 8 blades, and the fourth group has 2 blades.

[0038] Example 2

[0039] The present invention provides a reflux device, comprising two rows of blades installed between two cover plates, namely a first row of blades and a second row of blades, each row of blades comprising multiple blades 1, the second row of blades and the first row of blades being located on inner and outer circumferential rings; the multiple blades in the first row of blades having not exactly the same inlet mounting angle.

[0040] As a further embodiment, the multiple blades in the first row of blades are divided into N groups. The blades 1 in each group have the same inlet installation angle, and the blades 1 in different groups have different inlet installation angles. The inlet installation angles of the N groups of blades correspond one-to-one with the airflow angles of the return flow inlet under N different loads. The proportion of the number of blades 1 in each of the N groups of blades is consistent with the proportion of the weighting coefficients under N different loads.

[0041] As a further embodiment, the multiple blades 1 are divided into 4 groups, namely the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14. The inlet installation angle of the blades 1 in the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14 corresponds to the airflow angle at the inlet of the return valve under 100%, 75%, 50% and 25% load, respectively. The ratio of the number of blades in the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14 is consistent with the weighting coefficients under 100%, 75%, 50% and 25% load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Chiller Heat Pump Units for Commercial and Similar Applications", the weighting coefficients for 100%, 75%, 50%, and 25% loads are 2.3%, 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of blades in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 is 2.3%:41.5%:46.1%:10.1%. Furthermore, if the number of blades in a corresponding ratio is less than 1, it is increased to 1; otherwise, the nearest integer is used. For example, if the total number of blades in each blade row is 19, the first group has 1 blade, the second group has 8 blades, the third group has 8 blades, and the fourth group has 2 blades.

[0042] As a further embodiment, the weight of 100% load is usually small. For ease of design and manufacturing, the multiple blades 1 can be divided into 3 groups, namely the first blade group 11, the second blade group 12, and the third blade group 13. The inlet installation angle of the blades 1 in the first blade group 11, the second blade group 12, and the third blade group 13 corresponds to the airflow angle of the return valve inlet under 75%, 50%, and 25% load, respectively. The ratio of the number of blades in the first blade group 11, the second blade group 12, and the third blade group 13 is consistent with the weighting coefficients under 75%, 50%, and 25% load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Water-Cooling Heat Pump Units for Commercial and Similar Applications", the weighting coefficients for 75%, 50%, and 25% loads are 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of the number of blades in the first blade group 11, the second blade group 12, and the third blade group 13 is 41.5% : 46.1% : 10.1%. If the total number of blades in each blade row is 19, the first group has 8 blades, the second group has 9 blades, and the third group has 2 blades.

[0043] Example 3

[0044] The present invention provides a reflux device, comprising two rows of blades installed between two cover plates, namely a first row of blades and a second row of blades, each row of blades comprising multiple blades 1, the second row of blades and the first row of blades being located on inner and outer circumferential rings; the multiple blades in the second row of blades having not exactly the same inlet mounting angle.

[0045] As a further embodiment, the multiple blades in the first row of blades are divided into N groups. The blades 1 in each group have the same inlet installation angle, and the blades 1 in different groups have different inlet installation angles. The inlet installation angles of the N groups of blades correspond one-to-one with the airflow angles of the return flow inlet under N different loads. The proportion of the number of blades 1 in each of the N groups of blades is consistent with the proportion of the weighting coefficients under N different loads.

[0046] As a further embodiment, the multiple blades 1 are divided into 4 groups, namely the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14. The inlet installation angle of the blades 1 in the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14 corresponds to the airflow angle at the inlet of the return valve under 100%, 75%, 50% and 25% load, respectively. The ratio of the number of blades in the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14 is consistent with the weighting coefficients under 100%, 75%, 50% and 25% load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Chiller Heat Pump Units for Commercial and Similar Applications", the weighting coefficients for 100%, 75%, 50%, and 25% loads are 2.3%, 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of blades in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 is 2.3%:41.5%:46.1%:10.1%. Furthermore, if the number of blades in a corresponding ratio is less than 1, it is increased to 1; otherwise, the nearest integer is used. For example, if the total number of blades in each blade row is 19, the first group has 1 blade, the second group has 8 blades, the third group has 8 blades, and the fourth group has 2 blades.

[0047] As a further embodiment, the weight of 100% load is usually small. For ease of design and manufacturing, the blades can be divided into only three groups: the first blade group 11, the second blade group 12, and the third blade group 13. The inlet installation angle of the blades 1 in the first blade group 11, the second blade group 12, and the third blade group 13 corresponds to the airflow angle at the inlet of the return valve under 75%, 50%, and 25% load, respectively. The ratio of the number of blades in the first blade group 11, the second blade group 12, and the third blade group 13 is consistent with the weighting coefficients under 75%, 50%, and 25% load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Water-Cooling Heat Pump Units for Commercial and Similar Applications", the weighting coefficients for 75%, 50%, and 25% loads are 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of the number of blades in the first blade group 11, the second blade group 12, and the third blade group 13 is 41.5% : 46.1% : 10.1%. If the total number of blades in each blade row is 19, the first group has 8 blades, the second group has 9 blades, and the third group has 2 blades.

[0048] Example 4

[0049] This invention provides a reflux device, comprising two rows of blades installed between two cover plates, namely a first row of blades and a second row of blades, each row of blades comprising multiple blades 1, the second row of blades and the first row of blades being located on inner and outer circumferential rings; the inlet installation angles of the multiple blades in the first row of blades and the second row of blades are not exactly the same; wherein the arrangement of the first row of blades and the second row of blades can be the same or different.

[0050] As a further embodiment, the multiple blades in the first row of blades are divided into N1 groups. The blades 1 in each group have the same inlet installation angle, and the blades 1 in different groups have different inlet installation angles. The inlet installation angles of the N1 groups of blades correspond one-to-one with the airflow angles of the inlet of the return flower under N1 different loads. The proportion of the number of blades 1 in each group of N1 is consistent with the proportion of the weighting coefficients under N1 different loads.

[0051] As a further embodiment, the multiple blades in the second blade row are divided into N2 groups. Each group has blades 1 with the same inlet installation angle, while different groups have different inlet installation angles. The inlet installation angles of the N2 groups correspond one-to-one with the airflow angles at the inlet of the return flower under N2 different loads. The proportion of blades 1 in each group of the N2 groups is consistent with the proportion of the weighting coefficients under the N2 different loads. N1 and N2 can be the same or different.

[0052] As a further embodiment, the multiple blades 1 of the first or second blade cascade can be divided into four groups, namely the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14. The inlet installation angle of the blades 1 of the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 corresponds to the airflow angle of the return valve inlet under 100%, 75%, 50%, and 25% load, respectively. The ratio of the number of blades in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 is consistent with the weighting coefficients under 100%, 75%, 50%, and 25% load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Chiller Heat Pump Units for Commercial and Similar Applications", the weighting coefficients for 100%, 75%, 50%, and 25% loads are 2.3%, 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of blades in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 is 2.3%:41.5%:46.1%:10.1%. Furthermore, if the number of blades in a corresponding ratio is less than 1, it is increased to 1; otherwise, the nearest integer is used. For example, if the total number of blades in each blade row is 19, the first group has 1 blade, the second group has 8 blades, the third group has 8 blades, and the fourth group has 2 blades.

[0053] As a further embodiment, since the weight of 100% load is usually small, for ease of design and manufacturing, as a further embodiment, the multiple blades 1 of the first or second blade row can be divided into three groups, namely the first blade group 11, the second blade group 12, and the third blade group 13. The inlet installation angle of the blades 1 in the first blade group 11, the second blade group 12, and the third blade group 13 corresponds to the airflow angle of the return valve inlet under 75%, 50%, and 25% load, respectively. The ratio of the number of blades in the first blade group 11, the second blade group 12, and the third blade group 13 is consistent with the weighting coefficients under 75%, 50%, and 25% load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Water-Cooling Heat Pump Units for Commercial and Similar Applications", the weighting coefficients for 75%, 50%, and 25% loads are 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of the number of blades in the first blade group 11, the second blade group 12, and the third blade group 13 is 41.5% : 46.1% : 10.1%. If the total number of blades in each blade row is 19, the first group has 8 blades, the second group has 9 blades, and the third group has 2 blades.

[0054] Example 5

[0055] The present invention provides a reflux device, comprising a row of blades mounted between two cover plates, each row of blades comprising multiple blades 1 having not identical outlet mounting angles.

[0056] As a further embodiment, all blades in each row of the blade cascade are located on a circumference, wherein multiple blades 1 in at least one row of the blade cascade are divided into M groups, the blades 1 in each group have the same outlet installation angle, and the blades 1 in different groups have different outlet installation angles. The installation angles of the M groups of blades correspond one-to-one with the airflow angles of the return outlet under M different loads; the proportion of the number of blades 1 in each group of the M groups of blades is consistent with the weighting coefficients under the M different loads.

[0057] As a further embodiment, the multiple blades 1 are divided into four groups, namely the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14. The outlet installation angles of the blades 1 in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 correspond to the airflow angles at the outlet of the return valve under loads of 100%, 75%, 50%, and 25%, respectively. The ratio of the number of blades in the first blade group, the second blade group, the third blade group, and the fourth blade group is consistent with the weighting coefficients under loads of 100%, 75%, 50%, and 25%. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Chiller Heat Pump Units for Commercial and Similar Applications", the weighting coefficients for 100%, 75%, 50%, and 25% loads are 2.3%, 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of blades in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 is 2.3%:41.5%:46.1%:10.1%. Furthermore, if the number of blades in a corresponding ratio is less than 1, it is increased to 1; otherwise, the nearest integer is used. For example, if the total number of blades in each blade row is 19, the first group has 1 blade, the second group has 8 blades, the third group has 8 blades, and the fourth group has 2 blades.

[0058] As a further embodiment, the weight of 100% load is usually small. For ease of design and manufacturing, as a further embodiment, the multiple blades 1 of the first or second blade row can be divided into three groups, namely the first blade group 11, the second blade group 12, and the third blade group 13. The outlet installation angle of the blades 1 in the first blade group 11, the second blade group 12, and the third blade group 13 corresponds to the airflow angle of the return valve outlet under 75%, 50%, and 25% load, respectively. The ratio of the number of blades in the first blade group 11, the second blade group 12, and the third blade group 13 is consistent with the weighting coefficients under 75%, 50%, and 25% load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Water-Cooling Heat Pump Units for Commercial and Similar Applications", the weighting coefficients for 75%, 50%, and 25% loads are 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of the number of blades in the first blade group 11, the second blade group 12, and the third blade group 13 is 41.5% : 46.1% : 10.1%. If the total number of blades in each blade row is 19, the first group has 8 blades, the second group has 9 blades, and the third group has 2 blades.

[0059] Example 6

[0060] Based on Embodiment 5, the single row of blades installed between the two cover plates is replaced with two rows of blades, namely the first row of blades and the second row of blades, which are located on the inner and outer circumferences; the exit installation angle of the multiple blades in the first row of blades has the angle described in Embodiment 5.

[0061] Example 7

[0062] Based on Embodiment 5, the single row of blades installed between the two cover plates is replaced with two rows of blades, namely the first row of blades and the second row of blades, which are located on the inner and outer circumferences; the exit installation angle of the multiple blades in the second row of blades has the angle described in Embodiment 5.

[0063] Example 8

[0064] Based on Embodiment 5, the single-row blade assembly installed between the two cover plates is replaced with two rows of blades, namely a first row and a second row, located on inner and outer circumferential rings; the outlet installation angle of the multiple blades in the first and second rows has the angle described in Embodiment 5; wherein the arrangement of the first and second rows can be the same or different. A further embodiment is analogous to Embodiment 4, but the inlet installation angle is replaced with the outlet installation angle.

[0065] Example 9

[0066] The present invention provides a reflux device, comprising a row of blades mounted between two cover plates, the row of blades comprising multiple blades 1 having not identical mounting angles, the mounting angles including an inlet mounting angle and / or an outlet mounting angle.

[0067] The multiple blades are located on a circumference and divided into N groups. The blades 1 in each group have the same inlet installation angle, and the blades 1 in different groups have different inlet installation angles. The inlet installation angles of the N groups of blades correspond one-to-one with the airflow angles of the inlet of the return flower under N different loads. The proportion of the number of blades 1 in each of the N groups of blades is consistent with the weighting coefficients under the N different loads.

[0068] The multiple blades are located on a circumference and divided into M groups. The blades 1 in each group have the same outlet installation angle, while the blades 1 in different groups have different outlet installation angles. The installation angles of the M groups of blades correspond one-to-one with the airflow angles at the outlet of the return valve under M different loads. The proportion of the number of blades 1 in each of the M groups of blades is consistent with the weighting coefficients under the M different loads. M and N can be the same or different.

[0069] Example 10

[0070] Based on Example 9, the multiple blades 1 are divided into four groups: a first blade group 11, a second blade group 12, a third blade group 13, and a fourth blade group 14. The inlet installation angles of the blades 1 in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 correspond to the airflow angles at the inlet of the return valve under loads of 100%, 75%, 50%, and 25%, respectively. The ratio of the number of blades in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 is equal to 100%, 75%, and 25%, respectively. The weighting coefficients remain consistent at 50% and 25% loads. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Water-Cooled Heat Pump Units for Commercial and Similar Applications," the weighting coefficients for 100%, 75%, 50%, and 25% loads are 2.3%, 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of blades in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 is 2.3%:41.5%:46.1%:10.1%. Furthermore, if the number of blades in a corresponding ratio is less than 1, it is increased to 1; otherwise, the nearest integer is used. For example, if the total number of blades in each blade row is 19, the first group has 1 blade, the second group has 8 blades, the third group has 8 blades, and the fourth group has 2 blades.

[0071] And / or, the multiple blades 1 are divided into four groups, namely the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14. The outlet installation angle of the blades 1 in the first blade group 11, the second blade group 12, the third blade group 13 and the fourth blade group 14 corresponds to the airflow angle at the outlet of the return valve under 100%, 75%, 50% and 25% load, respectively. The ratio of the number of blades in the first blade group, the second blade group, the third blade group and the fourth blade group is consistent with the weighting coefficients under 100%, 75%, 50% and 25% load. According to the standard GB / T18430.1-2007 "Vapor Compression Cycle Water-cooled Heat Pump Units for Commercial and Similar Uses", the weighting coefficients for 100%, 75%, 50%, and 25% loads are 2.3%, 41.5%, 46.1%, and 10.1%, respectively. This means that the ratio of the number of blades in the first blade group 11, the second blade group 12, the third blade group 13, and the fourth blade group 14 is 2.3%:41.5%:46.1%:10.1%. Furthermore, if the number of blades in a corresponding ratio is less than 1, it is increased to 1; otherwise, the nearest integer is used.

[0072] Example 11

[0073] Based on embodiment 9 or 10, the single row of blades installed between the two cover plates is replaced with two rows of blades, namely the first row of blades and the second row of blades, which are located on the inner and outer circumferences; the mounting angle of the multiple blades in the first row of blades has the angle described in embodiment 9 or 10.

[0074] Example 12

[0075] Based on embodiment 9 or 10, the single row of blades installed between the two cover plates is replaced with two rows of blades, namely the first row of blades and the second row of blades, which are located on the inner and outer circumferential rings; the mounting angle of the multiple blades in the second row of blades has the angle described in embodiment 9 or 10.

[0076] Example 13

[0077] Based on embodiment 9 or 10, the single row of blades installed between the two cover plates is replaced with two rows of blades, namely the first row of blades and the second row of blades, which are located on the inner and outer circumferences; the mounting angle of the multiple blades in the first row of blades and the second row of blades has the angle described in embodiment 9 or 10; wherein the arrangement of the first row of blades and the second row of blades can be the same or different.

[0078] Example 14

[0079] Based on embodiments 1-13, the number of blades in the first row of blade cascades is the same as the number of blades in the second row of blade cascades; the multiple blades of the first row of blade cascades and the multiple blades of the second row of blade cascades are arranged in a staggered manner.

[0080] As a further embodiment, the blades in the first blade group, the second blade group, the third blade group, and the fourth blade group can be staggered or arranged in sequence.

[0081] Example 15

[0082] The present invention also relates to a centrifugal compressor, including a reflux device as described in any of Examples 1-14.

[0083] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0084] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0085] In this invention, unless otherwise explicitly specified and limited, the first feature being "on" or "below" the second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium.

[0086] In the description of this specification, references to terms such as "an embodiment" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A reflux rectifier comprising at least one row of blades mounted between two cover plates, characterized in that, Each row of blades includes multiple blades (1), wherein the multiple blades (1) in at least one row have not completely identical installation angles; the installation angle includes the inlet installation angle, all blades in each row of blades are located on a circumference, wherein the multiple blades (1) in at least one row of blades are divided into N groups, the blades (1) in each group have the same inlet installation angle, the blades (1) between different groups have different inlet installation angles, the angles of the inlet installation angles of the N groups of blades correspond one-to-one with the angles of the airflow angles at the inlet of the return flower under N different loads; the proportion of the number of blades (1) in each of the N groups of blades is consistent with the weighting coefficients under N different loads.

2. The reflux device according to claim 1, characterized in that, The installation angle includes the inlet installation angle and / or the outlet installation angle.

3. The reflux device according to claim 1, characterized in that, The multiple blades (1) are divided into four groups, namely the first blade group (11), the second blade group (12), the third blade group (13) and the fourth blade group (14). The inlet installation angle of the blades (1) of the first blade group (11), the second blade group (12), the third blade group (13) and the fourth blade group (14) correspond to the airflow angle of the return valve inlet under 100%, 75%, 50% and 25% load, respectively. The ratio of the number of blades in the first blade group (11), the second blade group (12), the third blade group (13) and the fourth blade group (14) is consistent with the weighting coefficients under 100%, 75%, 50% and 25% load.

4. The reflux device according to any one of claims 1 to 3, characterized in that, The installation angle includes the outlet installation angle. All blades in each row of the blade cascade are located on a circumference. Multiple blades (1) in at least one row of the blade cascade are divided into M groups. The blades (1) in each group have the same outlet installation angle. The blades (1) between different groups have different outlet installation angles. The installation angles of the M groups of blades correspond one-to-one with the airflow angles of the return outlet under M different loads. The proportion of the number of blades (1) in each group of the M groups of blades is consistent with the weighting coefficients under the M different loads.

5. The reflux device according to claim 4, characterized in that, The multiple blades (1) are divided into four groups, namely the first blade group (11), the second blade group (12), the third blade group (13) and the fourth blade group (14). The outlet installation angle of the blades (1) of the first blade group (11), the second blade group (12), the third blade group (13) and the fourth blade group (14) correspond to the airflow angle of the return outlet under 100%, 75%, 50% and 25% load, respectively. The ratio of the number of blades in the first blade group, the second blade group, the third blade group and the fourth blade group is consistent with the weighting coefficients under 100%, 75%, 50% and 25% load.

6. The reflux device according to claim 4, characterized in that, The leaf cascade consists of two columns, namely the first column of leaf cascade and the second column of leaf cascade, which are located on the inner and outer circumferences of the first column of leaf cascade.

7. The reflux device according to any one of claims 1-3 or 5, characterized in that, The leaf cascade consists of two columns, namely the first column of leaf cascade and the second column of leaf cascade, which are located on the inner and outer circumferences of the first column of leaf cascade.

8. The reflux device according to claim 7, characterized in that, The number of blades in the first row of leaf cascades is the same as the number of blades in the second row of leaf cascades, and the multiple blades of the first row of leaf cascades and the multiple blades of the second row of leaf cascades are arranged in a staggered manner.

9. A centrifugal compressor, characterized in that, Includes the reflux device as described in any one of claims 1-8.

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