Muffler, refrigeration compressor and refrigeration system

Abstract

The utility model discloses a kind of muffler, refrigeration compressor and refrigeration system, comprising: outer sleeve, axial center line two ends are respectively arranged sealing plate, outer sleeve and sealing plate are enclosed to form muffling cavity;At least two annular baffles, along the axial center line direction interval setting in muffling cavity and fixed in outer sleeve inner wall;At least two inner tubes, along the axial center line direction interval setting, the inner diameter one side of each annular baffle is fixedly sleeved on one of inner tube, and each inner tube is divided into preset proportion along the axial center line.No need to be covered with sound insulation cotton outside the exhaust pipe of unit, greatly reduce the total noise reduction cost of unit.Solve the problem of the current similar multi-frequency muffling large oil volume, without setting drain pipe and other drain components in muffler, reduce the associated influence of parts and drain pipeline to muffling performance, make structure simpler, easy to process and manufacture.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration unit technology, specifically to a muffler, refrigeration compressor and refrigeration system used in refrigeration units, home appliances and automobiles. Background Technology

[0002] As the operating speed range of variable frequency compressors gradually expands, noise issues become increasingly prominent. Taking a single-screw compressor as an example, the main noise source is exhaust pulsation noise. Assuming the upper limit of the unit's operating frequency is 70Hz, when the unit's operating frequency is 50-55Hz, the main noise is first-order exhaust pulsation noise, i.e., noise in the frequency band of 300-330Hz. When the unit's operating frequency rises to above 55-60Hz, the main noise is second-order exhaust pulsation noise, i.e., noise in the frequency band of 660-720Hz. This characteristic is particularly significant in large-displacement units. When the unit operates above 60Hz, the contributions of second-order and third-order exhaust pulsation are quite prominent, i.e., noise in the frequency bands of 720-840Hz and 1080-1260Hz. In other words, the silencer's silencing frequency needs to fully cover the low, medium, and high frequency ranges from 300-420Hz, 600-840Hz, and 900-1260Hz in order to achieve a good silencing effect and meet the requirements of continuous noise reduction for the variable frequency unit throughout the entire speed range.

[0003] Existing silencers are effective at reducing single noise peaks, but their performance is poor for multiple noise peaks and / or broadband peaks. This results in high noise levels at certain operating frequencies, sometimes necessitating the external covering of the unit with sound-absorbing cotton for further noise reduction, leading to high overall noise reduction costs. Therefore, designing a silencer with a wider noise reduction bandwidth to achieve continuous broadband noise reduction has become a pressing technical problem.

[0004] Currently, based on the principle of multi-cavity resonant silencing, there are broadband multi-cavity resonant intake mufflers and their operating methods. These include a centrally located cylindrical muffler shell with a perforated tube running through it, forming an inner cavity. Several baffles are arranged perpendicularly to the axis within this inner cavity, dividing it into several resonant cavities. The perforated tube has several rows of circumferentially arranged silencing holes, located in the center of each resonant cavity. However, this structure is prone to oil accumulation, has a large and protruding shape, making it difficult to cover with insulation material; furthermore, the different hole diameters of each silencing unit complicate manufacturing, and it is also related to oil leakage and drainage structures.

[0005] Another type of silencer assembly uses a two-chamber reactive silencer. Exhaust gas enters through the inlet pipe, then through the perforation into the front chamber. The airflow then passes through the inner tube into the rear chamber, and finally exits through the outlet pipe. By appropriately combining several basic silencing units with different structures and acoustic characteristics, a complex silencer structure can be formed, achieving good silencing effects over a wider frequency range. While silencing chambers of different sizes can suppress noise at different frequencies, this method has the following drawbacks: a large number of inner tubes, complex structure, high welding time, and difficulty in manufacturing; the shape is larger and more prominent than the inlet and outlet pipes, resulting in poor coordination and aesthetics, and it is inconvenient for insulation material coverage. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a muffler, refrigeration compressor and refrigeration system that form a wide-band noise reduction and a wider noise reduction range; solve the problem of large oil accumulation in similar multi-frequency mufflers, eliminate the need to set up drainage components such as drain pipes in the muffler, reduce the correlation between parts and drain pipes and noise reduction performance, make the structure simpler and easier to process and manufacture.

[0007] Furthermore, it eliminates the need to wrap the exhaust pipes of the generator set with sound insulation cotton, saving the cost of sound insulation cotton and thus greatly reducing the total noise reduction cost of the generator set.

[0008] The technical solution adopted in this utility model is: A silencer, comprising: The outer tube has sealing plates at both ends of the axial center line, and the outer tube and sealing plates together form a sound-absorbing cylindrical shell. At least two annular baffles are spaced apart in the silencing cavity along the axial centerline of the outer sleeve; the annular baffles are in full contact with the inner wall of the outer sleeve and are fixed to the inner wall of the outer sleeve in the annular circumference. At least two inner tubes are spaced apart along the axial centerline. One side of the inner diameter of each annular partition is fixedly fitted onto one of the inner tubes, and each inner tube is divided into a preset proportion along the axial centerline. Several through holes are provided on the annular baffle at least downstream of the silencer, so that the inner wall of the outer sleeve at the bottom directly cooperates with the through holes to define the drainage channel.

[0009] Therefore, the inner wall of the bottom outer casing directly serves as the bottom of the drain pipe. There is only a through hole between the partition and the inner wall of the bottom outer casing to limit the drain channel. No drain device needs to be installed between the partition and the liquid to be drained to the downstream position.

[0010] In the above technical solution, the length of each internal insertion tube in the upstream direction along the axial centerline is greater than the length of the internal insertion tube in the downstream direction along the axial centerline.

[0011] In the above technical solution, the extension length on the right side of each inner tube is less than the radial width of the corresponding connected annular partition, where the radial width is the difference between the outer diameter and the inner diameter of the annular partition.

[0012] In the above technical solution, each internal insertion tube is divided into the same or different preset proportions along the axial centerline.

[0013] In the above technical solutions, the inner diameters of each insert canister may be equal or unequal.

[0014] In the above technical solutions, the lengths of the internal insertion tubes may be equal or unequal.

[0015] In the above technical solution, at least several through holes are provided on the inner wall of the tube at the downstream position.

[0016] In the above technical solution, at least a number of through holes are provided on the annular diaphragm tube wall at the downstream position.

[0017] In the above technical solution, several through holes are provided on the annular diaphragm tube wall at the connection between the annular diaphragm tube wall and the outer tube, or near the connection between the annular diaphragm tube wall and the outer tube.

[0018] In the above technical solution, the sealing plate has through holes that connect the exhaust pipe and the internal muffler cavity respectively, and the ratio of the outer casing diameter to the exhaust pipe diameter is less than 1.3.

[0019] Based on the above-mentioned utility model, this utility model also provides a refrigeration compressor, particularly a single screw compressor, which adopts the above-mentioned silencer.

[0020] Based on the above-mentioned utility model, this utility model also provides a refrigeration system that uses the above-mentioned silencer.

[0021] In the aforementioned mufflers or compressors, both the muffler and the exhaust pipes at both ends are installed at an angle.

[0022] Compared with the prior art, the beneficial effects of this utility model are: It achieves multi-frequency or broadband noise reduction with a wider noise reduction range. Specifically, after the airflow enters the inlet of the silencer, part of the gas reaches the outlet of the silencer through the main channel of the sleeve, while the other part of the gas enters the noise reduction cavity through the through hole. The noise reduction cavity is a Helmholtz resonant cavity, so it has strong frequency selectivity and a larger noise reduction amplitude.

[0023] Through testing, this invention can achieve continuous noise reduction across the entire operating frequency range (40-70Hz) without any noise interruptions.

[0024] This silencer can meet the unit's noise target value, eliminating the need to wrap the unit's exhaust pipe with sound insulation cotton, thus saving the cost of sound insulation cotton and greatly reducing the unit's total noise reduction cost.

[0025] Because the first, second, and third silencing chambers have different volumes, each chamber corresponds to a different silencing frequency, thus achieving a wider silencing frequency range. Verification using the transmission loss curve shows that gas pressure pulsations are attenuated by the silencing chambers, effectively covering the first three levels of exhaust pulsation noise and achieving multi-frequency silencing. This results in continuous silencing across the entire operating frequency band, thereby reducing the overall noise of the unit. There is no need to wrap the unit with sound-absorbing cotton, significantly reducing the total noise reduction cost.

[0026] With a small pipe diameter ratio, it meets the miniaturization requirements of unit components, has better consistency and coordination with the exhaust pipe in appearance, greatly improves aesthetics, and makes it easy to cover the outside with insulation material.

[0027] By creating an oil drain hole, most of the deposited lubricating oil can be discharged from the muffler, reducing the amount of oil accumulation and thus minimizing its impact on the noise reduction effect.

[0028] Furthermore, the oil leakage hole has a smaller opening area than the silencing cavity, so its correlation with the silencing performance of the muffler is negligible. Finally, by setting up oil leakage holes, the chambers are connected, naturally forming a drainage channel. The accumulated oil can flow out along the holes under the action of gravity, eliminating the need to install drainage pipes or other drainage components in the muffler. This reduces the correlation between parts and drainage pipes and the muffler performance, making it simple to manufacture and low in cost. Attached Figure Description

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a schematic diagram of the overall structure of the muffler according to an embodiment of the present utility model.

[0030] Figure 2 This is a schematic diagram of the muffler in a half-section along the axial centerline of an embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram of the structure of the muffler with an oil leakage hole according to an embodiment of the present utility model.

[0032] Figure 4 This is a schematic diagram showing the specific location and shape of the oil leakage hole in the annular partition of one embodiment of the present invention.

[0033] Figure 5 This is a schematic diagram showing the specific location and shape of the oil leakage hole in the annular partition of another embodiment of this utility model.

[0034] Figure 6 A comparison diagram showing the effect of the oil leakage hole in this utility model on the oil level compared to the prior art without an oil leakage hole.

[0035] Figure 7This is a schematic diagram of the structure of the inner tube with an oil leakage hole according to an embodiment of this utility model.

[0036] Figure 8 This is a schematic diagram of the connection structure between the muffler and the exhaust pipe in an embodiment of this utility model.

[0037] Figure 9 This is a comparison chart of the transmission loss curves of the new structure silencer of this utility model and the existing structure. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0039] Example 1 According to one embodiment of the present invention, for example Figure 1-3 As shown, the muffler 1 includes: an outer tube 11, two sealing plates 12 located at both ends of the outer tube 11, two annular partitions 13 located inside the outer tube 11, and two inner tubes 14. The outer tube 11 and the sealing plates 12 form a silencing chamber. The sealing plates 12 have through holes 12A and 12B that connect to the exhaust pipe 15 or a connecting pipe, respectively. The two annular partitions 13 are spaced apart along the central axis of the outer tube 11 within the silencing chamber. Each annular partition 13 is fitted onto one inner tube 14, and each annular partition 13 divides the inner tube 14 into a predetermined proportion along the central axis. Thus, the silencing chamber between the two sealing plates 12 is sequentially divided along the central axis into a first silencing chamber 11A, a second silencing chamber 11B, and a third silencing chamber 11C that are interconnected.

[0040] The inner tube 14 is arranged along the central axis and is divided into two unconnected sections. Along the air intake direction, the first inner tube 141 is upstream, and the second inner tube 142 is downstream of the first inner tube 141. The first inner tube 141 is axially cylindrical, and the second inner tube 142 has a silencing hole 1421. Through holes 12A and 12B can be directly connected to the exhaust pipe and communicate with the internal silencing cavity.

[0041] Airflow enters the first anechoic chamber 11A through through-hole 12A, then flows into the second anechoic chamber 11B through the first inner tube 141, and then into the third anechoic chamber 11C through the second inner tube 142, finally exiting through through-hole 12B. Specifically, after entering the silencer inlet, part of the airflow reaches the silencer outlet through the main flow path of the outer tube, while the other part enters the anechoic chamber through the through-hole. The anechoic chamber is a Helmholtz resonant cavity, thus possessing strong frequency selectivity and a larger anechoic amplitude. Simultaneously, due to the different volumes of the first, second, and third anechoic chambers, each anechoic chamber corresponds to a different anechoic frequency, thereby achieving a wider anechoic frequency range. Gas pressure pulsations are attenuated by the anechoic chambers, thereby reducing pulsation noise and ultimately lowering the overall noise of the unit.

[0042] Example 2 Based on Example 1, the pipes containing through holes 12A and 12B can be either exhaust pipes or connecting pipes connected to exhaust pipe 15 (see Example 1). Figure 8 The exhaust pipe 15 at one end of the muffler 1 extends to the condenser inlet, and the exhaust pipe 15 at the other end extends to the compressor exhaust port.

[0043] The ratio of the outer casing 11 diameter to the exhaust pipe diameter is less than 1.3, preferably 1.25. This results in a small difference between the outer casing 11 diameter and the exhaust pipe diameter. For exhaust pipes requiring external insulation, an excessively large outer casing 11 diameter would make insulation of the section containing the muffler difficult. A smaller outer casing 11 diameter improves the overall aesthetics of the muffler installation within the exhaust pipe, making it less obtrusive and facilitating external insulation.

[0044] Example 3 In Embodiment 1 and / or Embodiment 2, the diameter of the inner insertion tube 142 can be the same or different. Preferably, inner insertion tubes 14 with the same diameter are used to facilitate production and processing. The lengths of the first inner insertion tube 141 and the second inner insertion tube 142 can be the same or different.

[0045] Example 4 Based on Embodiment 1 and / or Embodiment 2 and / or Embodiment 3, in some embodiments, the separation ratio of the first annular partition 131 and the second annular partition 132 within the outer sleeve 11 may be the same or different. The first annular partition 131 and the second annular partition 132 divide the anechoic chamber into a first anechoic chamber 11A, a second anechoic chamber 11B, and a third anechoic chamber 11C. The first annular partition 131 is sleeved outside the first inner insert 141, and the second annular partition 132 is sleeved outside the second inner insert 142. The connection method between the annular partition 13 and the outer sleeve 11 can be welding, abutment, adhesive bonding, threaded connection, etc. Similarly, the connection method between the annular partition 13 and the inner insert 14 can also be welding, abutment, adhesive bonding, threaded connection, etc.

[0046] Example 5 Based on Embodiments 1 and / or 2 and / or 3 and / or 4, the protruding length on the right side of the first inner tube 141 is less than the radial width of the first annular partition 131, and the protruding length on the right side of the second inner tube 142 is less than the radial width of the second annular partition 132. It should be noted that the radial width of the annular partition 13 refers to the difference between its outer diameter and inner diameter. This not only helps to improve the mid-to-high frequency noise reduction amplitude of the silencer but also facilitates processing. For example, if the annular partition 13 needs to be welded to the outer sleeve 11, the shorter length on one side of the inner tube 14 makes it easier for the welding torch to extend.

[0047] Example 6 Based on Embodiments 1 and / or 2 and / or 3 and / or 4 and / or 5, multiple silencing holes 1421 can be formed on the first inner tube 141 and the second inner tube 142. These silencing holes can be round, elliptical, or square. The silencing holes can be evenly or unequally spaced, and the sizes of the multiple silencing holes can be the same or different. Preferably, 4-8 rows of silencing holes can be formed on the second inner tube 142, with a hole diameter of φ10-20mm, evenly spaced circumferentially and arranged in two rows axially. This can effectively improve the high-frequency amplitude.

[0048] Example 7 Based on Example 1 and / or Example 2 and / or Example 3 and / or Example 4 and / or Example 5 and / or Example 6, such as Figure 3As shown, an oil drain hole 1311 is provided on the first annular baffle 13, and an oil drain hole 1321 is provided on the second annular baffle 132. The refrigerant gas flowing through the muffler carries lubricating oil, which accumulates over time in the muffler chamber. This accumulated oil occupies a portion of the muffler chamber volume, altering its silencing characteristics and weakening its silencing capacity. By providing oil drain holes, most of the accumulated lubricating oil can be discharged from the muffler, reducing its impact on the silencing effect. Specifically, the oil drain hole 1311 on the first annular baffle 131 guides the lubricating oil deposited in the first muffler chamber 11A to the second muffler chamber 11B, and the oil drain hole on the second annular baffle 132 guides the lubricating oil deposited in the second muffler chamber 11B to the third muffler chamber 11C. Excess lubricating oil can overflow through the lowest point of the through hole 12B and flow into the exhaust pipe from the outlet. This ensures that only a small amount of lubricating oil deposits in the third muffler chamber 11C, significantly reducing oil accumulation. Optionally, the oil leakage hole can be a round hole, a semi-circular hole, a square hole, etc. Preferably, an arc-shaped notch can be made at the edge of the annular partition 13 to form an oil leakage hole with the inner wall of the outer sleeve 11.

[0049] Such as 4 and Figure 5 These are different shapes of oil leakage holes on the edge of the annular partition: they can be square holes, arc holes, triangular holes, etc.; in addition, it is not necessary to make the holes on the edge as shown in the figure. They can be made in other positions on the partition, as long as the oil level position can cover the oil leakage hole.

[0050] Figure 6 The diagram shows a comparison of the effects of having an oil drain hole on the oil level with and without an existing technology. The diagram shows the oil accumulation in the existing technology without an oil drain hole: all three chambers will have a certain amount of oil accumulation. The diagram shows the oil accumulation with an oil drain hole, where the oil in the two upstream chambers can flow to the downstream chamber through the oil drain hole, reducing the amount of oil accumulation.

[0051] Example 8 Based on Embodiment 1 and / or Embodiment 2 and / or Embodiment 3 and / or Embodiment 4 and / or Embodiment 5 and / or Embodiment 6 and / or Embodiment 7, the oil leakage hole in this embodiment can also be formed on at least one inner tube, such as... Figure 7 As shown, an oil drain hole 1421 is provided near the oil level at the connection point between the inner tube 142 and the annular partition, close to the bottom. This results in a relatively low oil level, but the oil leakage effect is not as good as opening a hole on the partition. This oil drain hole is only used for oil leakage and has low requirements for hole diameter and arrangement, while the arrangement, diameter, and number of the inner tube silencer holes need to be designed and calculated.

[0052] Example 9 Based on Example 1 and / or Example 2 and / or Example 3 and / or Example 4 and / or Example 5 and / or Example 6 and / or Example 7 and / or Example 8, such as Figure 8As shown, because there is a height difference between the evaporator and the condenser, the exhaust pipe 15 of Unit 1 may be set at a certain angle, and the muffler 1 also needs to be tilted, such as at an angle of 5-45°.

[0053] The specific application effects are further explained below: Taking the original noise characteristics of a screw compressor unit (without a silencer) as an example, the upper limit of the unit's operating frequency is 70Hz. The main noise source is exhaust pulsation noise. According to noise test results, at low operating frequencies of 50-55Hz, the noise mainly comes from the first-order exhaust pulsation at 300-330Hz; at medium-high operating frequencies of 55-60Hz, the noise mainly comes from the second-order exhaust pulsation (660-720Hz); and at high operating frequencies of 65Hz and above, both the second- and third-order exhaust pulsation noises are quite prominent. The noise order changes with different operating frequencies, making the noise composition complex. To address this characteristic, existing silencers can cover the noise at operating frequencies of 50-55Hz, but at operating frequencies of 55Hz and above, the noise is still relatively high, indicating weak noise reduction capabilities.

[0054] The transmission loss curve of the muffler of this invention is compared with that of the existing structure described above. Figure 9 As shown, the horizontal axis represents the silencing frequency band, and the vertical axis represents the transmission loss amplitude, which represents the silencing capability. The higher the amplitude, the stronger the silencing capability. The effective silencing frequency bands of this invention are 290-370Hz, 590-770Hz, and 1050-1065Hz, while the effective silencing frequency bands of the existing structure are 280-355Hz and 580-600Hz. By comparing the transmission loss curves of the existing and new structures, it can be seen that the silencing effect of the new structure is significantly better than that of the existing structure, with a larger silencing bandwidth and higher silencing amplitude in the noise problem frequency band. In particular, the silencing bandwidth and amplitude of the second-order silencing are greatly improved, which can cover the entire operating frequency range of the variable frequency unit and solve the noise problem across the entire operating frequency range. The pressure pulsation of the gas is attenuated by the silencing cavity, which can effectively cover the exhaust pulsation noise of the first three orders mentioned above, achieving multi-frequency silencing, thereby achieving continuous silencing across the entire operating frequency band and reducing the overall noise of the unit. Furthermore, there is no need to cover the outside of the unit with sound insulation cotton, which greatly reduces the total noise reduction cost of the unit.

[0055] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A silencer, characterized in that... include: The outer tube has sealing plates at both ends of the axial center line, and the outer tube and sealing plates together form a sound-absorbing cylindrical shell. At least two annular baffles are spaced apart in the silencing cavity along the axial centerline of the outer sleeve; the annular baffles are in full contact with the inner wall of the outer sleeve and are fixed to the inner wall of the outer sleeve in the annular circumference. At least two inner tubes are spaced apart along the axial centerline. One side of the inner diameter of each annular partition is fixedly fitted onto one of the inner tubes, and each inner tube is divided into a preset proportion along the axial centerline. Several through holes are provided on the annular baffle at least downstream of the silencer, so that the inner wall of the outer sleeve at the bottom directly cooperates with the through holes to form a drainage channel.

2. The silencer according to claim 1, characterized in that: The length of each internal insertion tube in the upstream direction along the axial centerline is greater than the length of the internal insertion tube in the downstream direction along the axial centerline.

3. The silencer according to claim 1, characterized in that: The protruding length on the right side of each inner tube is less than the radial width of the corresponding connected annular septum, where the radial width is the difference between the outer diameter and the inner diameter of the annular septum.

4. The silencer according to claim 1, characterized in that: Each internal insertion tube is divided into the same or different preset proportions along the axial centerline.

5. The silencer according to claim 1, characterized in that: Several through holes should be provided on the inner wall of the cannula at least downstream.

6. The silencer according to claim 1, characterized in that: Several through holes are provided on the wall of the annular diaphragm tube at the connection between the annular diaphragm tube wall and the outer sleeve tube, or near the connection between the annular diaphragm tube wall and the outer sleeve tube.

7. The silencer according to claim 1, characterized in that: The sealing plate has through holes that connect the exhaust pipe and the internal muffler cavity, and the ratio of the outer casing diameter to the exhaust pipe diameter is less than 1.

3.

8. A refrigeration compressor, characterized in that: The silencer described in any one of claims 1-7 is used.

9. A refrigeration system, characterized in that: The silencer described in any one of claims 1-7 is used.

10. The refrigeration system according to claim 9, characterized in that: The muffler is tilted.

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