Screw compressor, refrigerating system and control method for refrigerating system

Abstract

This application discloses a screw compressor, comprising a screw compressor housing, a discharge chamber, at least one silencing channel, and at least one adjusting piston. The discharge chamber is defined by at least a portion of the screw compressor housing, and this portion forms a wall of the discharge chamber. The wall of the discharge chamber has at least one hole. The at least one adjusting piston is insertable into and movable within the at least one hole. The at least one silencing channel is formed by the at least one hole and the at least one adjusting piston, and is in fluid communication with the discharge chamber. The position of the at least one adjusting piston within the at least one hole determines the silencing length of the at least one silencing channel. The screw compressor of this application can adapt to different compressor operating conditions and reduce noise.

Description

[Technical Field]

[0001] Field of Invention

[0002] This application relates to compressors, and more specifically to a screw compressor. [Previous Technology]

[0003] Background of the Invention

[0004] The compressor includes a screw compressor. A screw compressor includes a housing and female and male rotors disposed within the housing. A compression chamber exists between the female and male rotors. During the rotation of the female and male rotors, the compression chambers become smaller, resulting in a smaller volume of gas contained within the compression chambers, thereby increasing the gas pressure and achieving gas compression. In a screw compressor, multiple spaced compression chambers exist between the female and male rotors; therefore, the compressed gas intermittently discharged from the compression chambers acts on the housing and is transmitted downstream, thereby generating airflow-induced vibration and noise. [Summary of the Invention]

[0005] Summary of the Invention

[0006] According to a first aspect of this application, a screw compressor is provided. The screw compressor includes a screw compressor housing, a discharge chamber, at least one silencing channel, and at least one adjusting piston. The discharge chamber is defined by at least a portion of the screw compressor housing, and the at least portion of the screw compressor housing defining the discharge chamber forms a wall of the discharge chamber, the wall of the discharge chamber having at least one hole. The at least one adjusting piston is insertable into and movable within the at least one hole. The at least one silencing channel is formed by the at least one hole and the at least one adjusting piston, and the at least one silencing channel is in fluid communication with the discharge chamber. The position of the at least one adjusting piston in the at least one hole determines the silencing length of the at least one silencing channel.

[0007] According to the screw compressor of the first aspect of this application, the at least one silencing channel is at least two silencing channels, and the at least one adjusting piston is at least two adjusting pistons. The screw compressor further includes an adjusting slider, and the at least two adjusting pistons are connected to the adjusting slider. The adjusting slider and the at least two adjusting pistons are configured such that when the adjusting slider reciprocates relative to the screw compressor housing, each of the at least two adjusting pistons is capable of reciprocating within a corresponding silencing channel, thereby changing the silencing length of each of the at least two silencing channels.

[0008] According to the screw compressor of the first aspect of this application, the at least one silencing channel is at least two silencing channels, and the at least one adjusting piston is at least two adjusting pistons. The at least two adjusting pistons are capable of reciprocating independently relative to the screw compressor housing to change the silencing length of each of the at least two silencing channels.

[0009] According to the screw compressor of the first aspect of this application, the at least two adjusting pistons are configured such that at any time during which the at least two adjusting pistons reciprocate relative to the screw compressor housing, each of the at least two silencing channels has a different silencing length.

[0010] According to the screw compressor of the first aspect of this application, the at least one orifice has an inlet end and a distal end opposite to the inlet end, and the at least one adjusting piston is insertable into the at least one orifice from the distal end. The distance between the top of the at least one adjusting piston and the inlet end is a noise-reducing length.

[0011] According to the screw compressor of the first aspect of this application, the at least one orifice has an inlet end and a distal end opposite to the inlet end, and the at least one adjusting piston is insertable into the at least one orifice from the distal end. Each of the at least one adjusting piston has a recess extending from one end face of the at least one adjusting piston to the other end, the distance between the bottom of the recess of the at least one adjusting piston and the inlet end is a noise-reducing length.

[0012] According to the screw compressor of the first aspect of this application, the screw compressor further includes an adjusting box, which is disposed outside the screw compressor housing and defines an adjusting cavity. The adjusting slider is disposed in the adjusting box and divides the adjusting cavity into a first receiving portion and a second receiving portion, the first receiving portion being formed on the side of the adjusting slider near the screw compressor housing, and the second receiving portion being formed between the adjusting box and the adjusting slider.

[0013] According to a second aspect of this application, this application also provides a screw compressor, the screw compressor including a screw compressor housing, a discharge cavity, an adjusting box, an adjusting piston, and a silencing channel. The discharge cavity is defined by at least a portion of the screw compressor housing, the at least portion of the screw compressor housing defining the discharge cavity forming a wall of the discharge cavity, and the wall of the discharge cavity has a hole. The adjusting box is disposed outside the screw compressor housing and defines the adjusting cavity, the adjusting cavity forming a continuous channel with the hole. The adjusting piston is insertable into the continuous channel and is movable within the continuous channel. The silencing channel is formed by the hole, the adjusting piston, and the adjusting box, and the silencing channel is in fluid communication with the discharge cavity. The position of the at least one adjusting piston in the hole and the adjusting cavity determines the silencing length of the silencing channel.

[0014] According to the screw compressor of the second aspect of this application, the screw compressor further includes at least one plate disposed in the discharge cavity and covering the hole. The at least one plate has a plurality of through holes to allow fluid communication between the discharge cavity and the silencer channel.

[0015] According to the screw compressor of the second aspect of this application, the adjusting piston is disposed in the adjusting box and divides the adjusting cavity into a first receiving portion and a second receiving portion, the first receiving portion being formed on the side of the adjusting piston near the screw compressor housing, and the second receiving portion being formed between the adjusting box and the adjusting piston.

[0016] According to a third aspect of this application, this application also provides a refrigeration system including the aforementioned screw compressor and a lubricant circuit. The lubricant circuit is connected to the screw compressor. The second receiving portion is disconnectably connected to the lubricant circuit and disconnectably connected to the inlet of the screw compressor. Furthermore, the refrigeration system is configured to provide lubricant from the lubricant circuit to the second receiving portion to move the adjusting piston toward the inlet end, and to introduce lubricant from the second receiving portion into the inlet of the screw compressor to move the adjusting piston away from the inlet end.

[0017] The screw compressor of this application can adapt to different compressor operating conditions and reduce noise.

[0018] Other features, advantages, and embodiments of this application may be set forth or become apparent from the following detailed description, accompanying drawings, and claims. Furthermore, it should be understood that the above description and the following detailed description are exemplary and intended to provide further explanation, without limiting the scope of the claimed application. However, the detailed description and specific examples only indicate preferred embodiments of this application. Various changes and modifications within the spirit and scope of this application will become apparent to those skilled in the art through these detailed descriptions.

Implementation Method

[0019] Detailed Implementation

[0020] Various specific embodiments of the present application will now be described with reference to the accompanying drawings, which form part of this specification. It should be understood that although terms indicating direction, such as "front," "rear," "upper," "lower," "outer," "bottom," etc., are used herein to describe various exemplary structural parts and elements of the present application, their use is merely for illustrative purposes, and these terms are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this application can be arranged in different orientations, these terms indicating direction are illustrative only and should not be considered as limiting.

[0021] FIG1A is a perspective view of a screw compressor 100 according to an embodiment of the present application, viewed from front to back; FIG1B is a cross-sectional view of the screw compressor 100 shown in FIG1A, viewed from back to front along the length direction of the screw compressor; FIG1C is a cross-sectional view of the screw compressor 100 shown in FIG1A, cut along the width direction of the screw compressor to the discharge cavity 113 of the screw compressor 100. As shown in FIG1A-1C, the screw compressor 100 includes a screw compressor housing 101. The screw compressor housing 101 defines a rotor cavity 111 and a discharge cavity 113. The rotor cavity 111 and the discharge cavity 113 are interconnected through a communication port 112.

[0022] Specifically, a pair of rotors are disposed in rotor cavity 111. The pair of rotors includes a male rotor 121 and a female rotor (not shown). A compression cavity (not shown) is formed between the male rotor 121 and the female rotor, which is surrounded by the tooth surfaces of the male rotor 121 and the female rotor. The compression cavity is in fluid communication with the discharge cavity 113 through the communication port 112. When the screw compressor 100 is operating, gas enters the compression cavity between the male rotor 121 and the female rotor from the inlet of the screw compressor 100 (see Figure 3, i.e., screw compressor inlet 302). As the male rotor 121 and the female rotor rotate, the compression cavity gradually decreases and moves toward the communication port 112. When the compression cavity moves to be in fluid communication with the communication port 112, the compressed gas in the compression cavity flows into the discharge cavity 113 through the communication port 112. The intermittently formed compressed fluid temporarily remains in the discharge chamber 113, forming a buffer and thus creating a relatively stable airflow. This airflow exits the screw compressor 100 through the outlet 188 (see Figure 3, i.e., screw compressor outlet 306) located on the discharge chamber 113. The wall of the discharge chamber 113 has eight holes 122 arranged in two rows, with four holes 122 in each row. All eight holes 122 penetrate the wall of the discharge chamber 113.

[0023] As shown in Figure 1A, the screw compressor 100 also includes an adjustment box 132. The adjustment box 132 is disposed on the screw compressor housing 101 and covers eight holes 122. The components provided in the adjustment box 132 can cooperate with the eight holes 122, thereby reducing the noise generated by the gas discharged from the screw compressor 100. The adjustment box 132 is provided with a communication port 134, which is connected to the lubricant system through a connecting pipe 150. The adjustment box 132, the components provided in the adjustment box 132, and the holes provided on the wall of the discharge cavity 113 form a sound-absorbing structure, the specific cooperation relationship of which will be explained with reference to Figure 2.

[0024] FIG2 is a cross-sectional view of the first embodiment of the noise reduction structure shown in FIG1A, showing the fitting relationship between the regulating box 132, the components within the regulating box 132, and the screw compressor housing 101. As shown in FIG2, eight holes 122 are provided on the wall of the discharge cavity 113. Each of the eight holes 122 penetrates the wall of the discharge cavity 113. The regulating box 132 includes a generally rectangular bottom wall 242, side walls 244, and connecting wall 246. The side walls 244 surround the bottom wall 242 and extend upward from the circumferential edge of the bottom wall 242, and the connecting wall 246 extends outward from the upper edge of the side walls 244. The regulating box 132 is disposed on the outside of the screw compressor housing 101 and covers the eight holes 122. The connecting wall 246 abuts against the screw compressor housing 101 and is connected to the outside of the screw compressor housing 101 by means of connecting parts (not shown) or welding. The bottom wall and side walls 244 of the regulating box 132, together with the screw compressor housing 101, form an regulating cavity 204. The regulating cavity 204 is in fluid communication with eight holes 122.

[0025] The screw compressor 100 also includes an adjusting slider 202 and eight adjusting pistons 222. Each of the eight adjusting pistons 222 is a cylindrical body connected to the upper surface of the adjusting slider 202, thereby enabling the adjusting slider 202 and the eight adjusting pistons 222 to move together. The shape of each of the eight adjusting pistons 222 matches a corresponding one of the eight holes 122, thereby enabling each of the eight adjusting pistons 222 to be inserted into a corresponding one of the eight holes 122. The eight adjusting pistons 222 and the eight holes 122 are also configured such that gas in the discharge chamber 113 does not flow into the adjusting chamber 204 when the eight adjusting pistons 222 move up and down in the eight holes 122. The eight holes 122 have an inlet end and a distal end opposite to the inlet end. The inlet end is formed by the wall of the eight holes 122 and is in fluid communication with the discharge chamber 113. The eight adjusting pistons 222 are inserted into the corresponding holes 122 from the distal end. Eight adjusting pistons 222 and eight holes 122 respectively form eight silencing channels 288. Specifically, one end of the silencing channel 288 is defined by an inlet end, and the other end is defined by the tops of the eight adjusting pistons 222. As the adjusting pistons 222 move up and down in the holes 122, the distance between the inlet end and the tops of the eight adjusting pistons 222 changes, thereby giving the silencing channels 288 different lengths. When the top surface of the adjusting piston 222 is flush with the inner side of the wall of the hole 122, the length of the silencing channel 288 is 0. The circumferential dimension of the adjusting slider 202 is configured to match the side wall 244 of the adjusting box 132, thereby dividing the adjusting cavity 204 into a first receiving portion 231 and a second receiving portion 232 that are spaced apart from each other by adjusting the slider 202. The first receiving portion 231 is formed on the side of the adjusting slider 202 near the screw compressor housing 101 (i.e., the upper side of the adjusting slider 202), and the second receiving portion 232 is formed between the adjusting slider 202 and the bottom wall 242 of the adjusting box 132 (i.e., the lower side of the adjusting slider 202).

[0026] A connecting port 134 is provided on the bottom wall 242 of the regulating box 132 for connection to a pressure source. In an embodiment of this application, the connecting port 134 is connected to a lubricant circuit via a connecting pipe 150 (see FIG. 1A), thereby allowing lubricant to flow into the second receiving portion 232 through the connecting port 134. The pressure in the first receiving portion 231 is approximately ambient pressure (i.e., one atmosphere).

[0027] The screw compressor 100 also includes a spring 252 for providing auxiliary force for the upward movement of the adjusting slider 202 within the adjusting box 132 (i.e., toward the screw compressor housing 101) and limiting the downward movement of the adjusting slider 202. Specifically, one end of the spring 252 is connected to the lower surface of the adjusting slider 202, and the other end of the spring 252 is connected to the bottom wall 242 of the adjusting box 132. When the distance between the bottom of the adjusting slider 202 and the top of the bottom wall 242 is a predetermined distance H, the spring 252 is in a free state, i.e., the spring 252 is neither compressed nor stretched, and does not apply force to the adjusting slider 202. When the distance between the bottom of the adjusting slider 202 and the top of the bottom wall 242 is greater than the predetermined distance H, the spring 252 is stretched, and it applies a downward pulling force (i.e., away from the screw compressor housing 101) to the adjusting slider 202. When the distance between the bottom of the adjusting slider 202 and the top of the bottom wall 242 is less than a predetermined distance H, the spring 252 is compressed, which exerts an upward (i.e., toward the screw compressor housing 101) thrust on the adjusting slider 202.

[0028] When the screw compressor 100 is running, the refrigerant is compressed into a high-temperature, high-pressure gas within the screw compressor 100. The compressed gas enters the discharge chamber 113, generating exhaust pulsations with high acoustic energy. These exhaust pulsations not only cause vibration and noise but also create secondary sound sources for equipment downstream of the screw compressor 100 within the refrigeration system.

[0029] The screw compressor 100 of this application has a silencing channel 288 on the wall of its discharge cavity 113, which can control the propagation of noise at the location closest to the noise source. When parameters such as the operating frequency, discharge pressure, and discharge temperature of the screw compressor 100 change, the frequency corresponding to the peak energy of the discharge pulsation of the screw compressor 100 is different, and the wavelength corresponding to the peak energy is also different. The length of the silencing channel 288 in the silencing structure of this application can be adjusted to adapt to the peak wavelength under different operating conditions, so as to reduce the peak energy of the discharge pulsation and effectively silence the noise.

[0030] Figure 3 shows a partial system diagram of a refrigeration system 300 using the screw compressor 100 of this application. In this embodiment, a lubricant is used as the power source to drive the movement of the adjusting slider 202 and the eight adjusting pistons 222.

[0031] As shown in Figure 3, the refrigeration system 300 includes a screw compressor 100. The screw compressor 100 includes a screw compressor inlet 302, a lubricant inlet 304, and a screw compressor outlet 306. The screw compressor inlet 302 is in fluid communication with the rotor cavity 111 and is used to receive refrigerant from the evaporator (not shown) of the refrigeration system 300. The lubricant inlet 304 is in fluid communication with the rotor cavity 111 and is used to receive lubricant from the lubricant separator 312. The screw compressor outlet 306 is in fluid communication with the discharge cavity 113 and is used to discharge the compressed refrigerant and lubricant from the screw compressor 100.

[0032] The refrigeration system 300 also includes a lubricant separation device 312. The lubricant separation device 312 is used to separate the refrigerant from the lubricant. Specifically, the lubricant separation device 312 includes a lubricant separation device inlet 314, a lubricant outlet 316, and a refrigerant outlet 318. The lubricant separation device inlet 314 is connected to the screw compressor outlet 306 via a first channel 322, and is used to receive the compressed refrigerant and lubricant. After passing through the lubricant separation device 312, the lubricant flows out from the lubricant outlet 316, while the refrigerant flows out from the refrigerant outlet 318. The lubricant outlet 316 is in fluid communication with the screw compressor lubricant inlet 304 via a second channel 324, and is used to introduce the lubricant into the rotor cavity 111 of the screw compressor 100, thereby lubricating the male rotor 121 and the female rotor. The refrigerant outlet 318 flows to the condenser (not shown) of the refrigeration system 300. Thus, the screw compressor 100, the first channel 322, the lubricant separator 312, and the second channel 324 form a lubricant circuit.

[0033] The refrigeration system 300 also includes a switching device 332. The switching device 332 includes a first port 326, a second port 327, a third port 328, a first switching device channel 341, and a second switching device channel 342. The first switching device channel 341 connects the first port 326 and the third port 328, and the second switching device channel 342 connects the second port 327 and the third port 328. When the switching device 332 is in the first position, the first switching device channel 341 is connected while the second switching device channel 342 is disconnected. When the switching device 332 is in the second position, the first switching device channel 341 is disconnected while the second switching device channel 342 is connected. The first port 326 of the switching device 332 is in fluid communication with the lubricant outlet 316 for introducing high-pressure lubricant. The second port 327 of the switching device 332 is in fluid communication with the screw compressor inlet 302 for allowing high-pressure lubricant to flow into the screw compressor 100. The third port 328 of the switching device 332 is connected to the communication port 134 of the regulating box 132 via the connecting pipe 150. A solenoid valve 360 ​​is provided on the connecting pipe 150. The opening and closing of the solenoid valve 360 ​​can be controlled, thereby controlling the connection and disconnection of the connecting pipe 150.

[0034] The screw compressor 100 also includes two acoustic sensors 351 and 352. In this embodiment, the acoustic sensors 351 and 352 are arranged in the first channel 322. The detection ends (not shown) of the acoustic sensors 351 and 352 are in fluid communication with the first channel 322 to detect the exhaust pulsation energy value of the gas discharged from the screw compressor 100. Those skilled in the art will understand that since the two acoustic sensors 351 and 352 are used to detect the exhaust pulsation energy value of the gas discharged from the screw compressor 100, the detection ends of the two acoustic sensors 351 and 352 can also be arranged in the discharge cavity 113.

[0035] The screw compressor 100 also includes a position sensor 355 for detecting the distance between the adjusting slider 202 and the bottom wall 242 of the adjusting box 132. Since the wall thickness of the screw compressor housing 101, the distance from the bottom wall 242 of the adjusting box 132 to the screw compressor housing 101, and the lengths of the eight adjusting pistons 222 are all fixed values ​​and known, the real-time noise reduction length can be obtained based on the distance between the adjusting slider 202 and the bottom wall 242 of the adjusting box 132 detected by the position sensor 355.

[0036] The refrigeration system 300 also includes a control device 301. The control device 301 is communicatively connected to acoustic sensors 351 and 352, a position sensor 355, a solenoid valve 360, and a switching device 332. The control device 301 can obtain the exhaust pulsation energy value of the gas discharged from the screw compressor 100 from the acoustic sensors 351 and 352, thereby calculating the target noise reduction length. The control device 301 can obtain the distance between the adjusting slider 202 and the bottom wall 242 of the adjusting box 132 from the position sensor 355, thereby calculating the real-time noise reduction length. The control device 301 can monitor the real-time noise reduction length and adjust the position of the eight adjusting pistons 222 according to the relationship between the real-time noise reduction length and the target noise reduction length. For example, when the real-time noise reduction length is less than or greater than the target noise reduction length, the eight adjusting pistons 222 are moved downward or upward. When the real-time noise reduction length is equal to the target noise reduction length, the eight adjusting pistons 222 stop moving and remain in their current position. The control device 301 can also control the opening or closing of the solenoid valve 360, and control the switch device 332 to be in the first position or the second position.

[0037] Figure 4 shows the flow path of the lubricant in the refrigeration system 300 when the adjusting slider 202 moves upward. The arrows indicate the flow path of the lubricant. As shown in Figure 4, when the adjusting slider 202 needs to move upward, the control device 301 switches the switching device 332 to the first position, thereby connecting the first channel 341 and disconnecting the second channel 342. The control device 301 also opens the solenoid valve 360, thereby connecting the connecting pipe 150. Thus, the lubricant flows out from the lubricant outlet 316 of the lubricant separator 312 and is divided into two paths. One path of lubricant sequentially enters the second receiving portion 232 through the first port 326, the third port 328 of the switching device 332, and the connecting port 134 of the adjusting box 132, thereby controlling the movement of the adjusting slider 202 and the eight adjusting pistons 222. The other path of lubricant flows according to the lubricant circuit. Specifically, it enters the screw compressor 100 through the second channel 324 from the screw compressor lubricant inlet 304.

[0038] Figure 5 shows the flow path of the lubricant in the refrigeration system 300 when the adjusting slider 202 is moved downward. The arrows indicate the flow path of the lubricant. As shown in Figure 5, when the adjusting slider 202 needs to be moved downward, the control device 301 switches the switching device 332 to the second position, thereby connecting the second channel 342 and disconnecting the first channel 341. The control device 301 also opens the solenoid valve 360, thereby connecting the connecting pipe 150. In this way, in addition to one lubricant flowing according to the lubricant circuit, the lubricant flowing out from the second receiving part 232 flows into the screw compressor 100 through the connecting port 134, the third port 328 and the second port 327 of the adjusting box 132 from the screw compressor inlet 302.

[0039] Figure 6 shows a schematic diagram of the principle of controlling the movement of the adjusting slider 202 and the adjusting piston 222. As shown in Figure 6, eight adjusting pistons 222 and adjusting slider 202 are interconnected, so that the eight adjusting pistons 222 and adjusting slider 202 can move together. The direction of movement of the eight adjusting pistons 222 and adjusting slider 202 depends on the pressure difference between the upper and lower sides of the eight adjusting pistons 222 and adjusting slider 202. When the switching device 332 is in the first position, the second receiving part 232 is filled with high-pressure lubricant. The pressure on the lower side of the eight adjusting pistons 222 and adjusting slider 202 is greater than the pressure on the upper side of the eight adjusting pistons 222 and adjusting slider 202, and the adjusting slider 202 and adjusting piston 222 move upward, thereby reducing the length of the silencing channel 288. When the switching device 332 is in the second position, the second receiving portion 232 is connected to the low-pressure end (i.e., the suction end) of the screw compressor 100, and lubricant flows out of the second receiving portion 232. The adjusting slider 202 and the adjusting piston 222 move downward, thereby increasing the length of the silencing channel 288. When the silencing length of the silencing channel 288 is equal to the target silencing length, the control device 301 closes the solenoid valve 360, thereby keeping the adjusting slider 202 and the adjusting piston 222 in their current positions.

[0040] Thus, the screw compressor 100 of this application can utilize the lubricant circuit in the refrigeration system 300 to control the length of the muffler channel 288 by controlling the position of the regulating piston 222 without the need for an additional drive source.

[0041] As an example, the peak wavelength of the exhaust pulsation can be calculated from the signals collected by the two acoustic sensors 351 and 352, thereby determining the length of the silencing channel 288 to achieve the silencing effect. Specifically, the detection ends (not shown) of the two acoustic sensors 351 and 352 are set in the first channel 322 to obtain the exhaust pulsation energy value (e.g., auto-power spectrum, cross spectrum). Subsequently, the spectral data of the exhaust pulsation energy traveling downwards is obtained by the following formula: where and are the auto-power spectra of the signals picked up by the acoustic sensors 351 and 352, and are the cross spectrum of the signals picked up by the acoustic sensors 351 and 352, k is the wavenumber, is the center distance between the acoustic sensors 351 and 352, and is the spectral data of the exhaust pulsation energy.

[0042] Subsequently, the frequency corresponding to the peak energy is extracted based on the calculated spectrum data of the exhaust pulsation energy, and the speed of sound in the exhaust fluid is obtained from the operating parameters of the screw compressor 100 (e.g., exhaust pressure, exhaust temperature), thereby calculating the wavelength corresponding to the peak energy. The corresponding target silencing length is calculated based on this wavelength. The control device 301 controls the position of the adjusting piston 222 according to the calculated target silencing length, so that the actual length of the silencing channel 288 is consistent with the target silencing length.

[0043] Thus, the noise reduction structure in the screw compressor 100 of this application can effectively reduce the exhaust pulsation in the discharge cavity 113, and can automatically adapt to different operating conditions to reduce the pulsation with prominent energy.

[0044] It should be noted that although the wall of the discharge cavity 113 in this application is provided with eight holes, any number of holes and the number of corresponding adjusting pistons are within the protection scope of this application.

[0045] Eight silencing channels 288 are formed in the silencing structure shown in Figure 2 (only four silencing channels are shown in Figure 2, the other four are not shown). Each of the eight silencing channels 288 has the same length and can be used to silencing the wavelength range corresponding to the peak energy. Specifically, when the sound wave matching the silencing length is transmitted to the inlet end of the silencing channel, most of the sound wave is reflected due to the acoustic impedance mismatch, and a portion is converted into heat energy and absorbed due to the damping effect, so that only a small portion of the sound wave can continue to propagate downstream to achieve silencing. As can be seen from Figure 1B, multiple silencing channels are arranged in two rows and set along the sound wave travel path (e.g., from the connection port 112 to the outlet of the screw compressor 100). Compared with only one silencing channel, the multiple silencing channels in the screw compressor 100 of this application set along the sound wave travel path can perform multiple silencing operations on the same wavelength range, thereby greatly reducing the noise generated by the gas discharged from the screw compressor 100.

[0046] Figure 7 shows another embodiment of the drive mechanism for driving the adjusting slider 202 and the eight adjusting pistons 222. The silencing structure shown in Figure 7 is largely the same as that shown in Figure 6, and will not be described again here. The difference from that shown in Figure 6 is that the adjusting slider 202 and the eight adjusting pistons 222 in Figure 6 are driven by lubricant, while the adjusting slider 202 and the eight adjusting pistons 222 in Figure 7 are driven by a drive device 701. More specifically, in the embodiment shown in Figure 6, the adjusting box 132 is provided with a communication port 134 for receiving lubricant. The movement of the adjusting slider 202 is controlled by controlling the lubricant contained in the second receiving part 232, thereby controlling the length of the silencing channel 288. This control method does not require an external power source; the length of the silencing channel 288 can be controlled using the lubricant in the refrigeration system 300, thereby reducing production and operating costs. In the embodiment shown in Figure 7, the length of the silencing channel 288 is controlled by the movement of the adjusting slider 202 through the drive device 701. This control method requires less piping and can directly control the length of the silencer channel 288 through the drive device 701.

[0047] Specifically, the drive unit 701 includes a main body 703 and a rod 702. The rod 702 can extend and retract from the main body 703 relative to the main body 703. The adjustment box 132 is provided with a receiving port 710 for receiving the rod 702 of the drive unit 701. The rod 702 extends into the adjustment cavity 204 from the receiving port 710. The distal end of the rod 702 is connected to the adjustment slider 202, so that when the rod 702 extends, eight adjustment pistons 222 move together with the adjustment slider 202 toward the screw compressor housing 101, thereby reducing the length of the silencer channel 288. When the rod 702 retracts, eight adjustment pistons 222 move together with the adjustment slider 202 away from the screw compressor housing 101, thereby increasing the length of the silencer channel 288. As an example, the drive unit 701 is a motor. The control unit 301 is communicatively connected to the drive unit 701, thereby controlling the start and stop of the drive unit 701.

[0048] Figure 8 shows a cross-sectional view of a second embodiment of the silencing structure. The silencing structure shown in Figure 8 is similar to that shown in Figure 2, and will not be described again. The difference from Figure 2 is that each of the adjusting pistons 822 shown in Figure 8 has a blind hole 882. In other words, each of the adjusting pistons 822 has a recess extending from one end to the other. The diameter of the recess is slightly smaller than the diameter of the adjusting piston 822. In this case, the silencing channel 888 is formed by a portion of the eight holes 122 starting from the inlet end together with the blind holes 882. When the adjusting piston 822 moves within the holes 122, a longer silencing length can be provided, thus adapting to longer wavelength sound waves. More specifically, in the embodiment of the silencing structure shown in Figure 2, the length of the silencing channel 288 is determined by the distance from the inlet end to the top of the adjusting piston 222. This is suitable for applications where the screw compressor housing 101 has a thicker wall or where the target silencing length is shorter. In the embodiment of the noise reduction structure shown in Figure 8, the noise reduction channel 888 is determined by the distance from the inlet end to the bottom of the adjusting piston recess. This is suitable for applications where the screw compressor housing 101 has a thin wall thickness or where the target noise reduction length is long, in order to reduce noise with longer wavelengths.

[0049] It should be noted that when the length of the adjusting piston 822 is greater than the length of the eight holes 122, the adjusting piston 822 can protrude inward relative to the inner wall of the discharge cavity 113. At this time, the length of the silencing channel 888 is determined by the depth of the blind hole 882 in the adjusting piston 822.

[0050] Figure 9 shows a cross-sectional view of a third embodiment of the silencing structure. The silencing structure shown in Figure 9 is similar to that shown in Figure 2, and will not be described again. The difference from Figure 2 is that the eight adjusting pistons 922 shown in Figure 9 have different lengths. Therefore, the eight silencing channels 988 also have different lengths. The eight silencing channels 988 of different lengths can respectively silencing sound waves of different wavelengths, achieving simultaneous reduction of pulsations at multiple frequencies with prominent energy, thereby broadening the silencing range. As an example, the lengths of some of the eight silencing channels 988 in the embodiment shown in Figure 9 can be designed to match the wavelength corresponding to the peak energy, thereby reducing noise at the peak energy. The lengths of the remaining silencing channels 988 can be designed to match the wavelength near the peak energy, thereby reducing other noise near the peak energy.

[0051] Figure 10 shows a cross-sectional view of a fourth embodiment of the silencing structure. As shown in Figure 10, eight holes 122 are provided on the wall of the discharge cavity 113. Each of the eight holes 122 penetrates the wall of the discharge cavity 113. The regulating box 1032 is a cuboid with eight regulating cavities 1002. The eight regulating cavities 1002 extend downward from one side of the regulating box 1032. The eight regulating cavities 1002 have the same circumferential dimension as the eight holes 122 and are arranged in a one-to-one correspondence with the eight holes 122 to form a continuous channel. Eight regulating pistons 1022 are respectively arranged in one of the corresponding eight channels, dividing each of the regulating cavities 1002 into a first receiving portion 1031 and a second receiving portion 1033. At this time, the eight silencing channels are formed by the eight holes 122 from the inlet end to the end face of the regulating piston 1022. The regulating box 1032 has eight communication ports 1034 on the side opposite to the eight regulating cavities 1002, corresponding to the second receiving portion 1033, for connection to the lubricant system to control the position of each regulating piston 1022 in the channel. The eight communication ports 1034 are in fluid communication with the eight regulating cavities 1002 respectively. Each regulating piston 1022 has a protrusion at its bottom as a limit for downward movement. The refrigeration system may include multiple third channels, multiple fourth channels, and multiple switching devices corresponding to the number of regulating pistons 1022, to control the position of each regulating piston 1022 in the channel using lubricant in the lubricant circuit. The specific control method is similar to that described in Figures 3-5 and will not be repeated here. When the screw compressor 100 is running, the position of each regulating piston 1022 in the channel can be independently controlled, thereby forming silencing channels with different silencing lengths. The silencing channels of different lengths can silence noise of different wavelengths, thus not only silencing wavelengths corresponding to peak energy, but also silencing wavelengths corresponding to other higher energies, thereby broadening the scope of silencing.

[0052] The silencing structures shown in Figures 2-10 all have silencing channels on the inner wall of the discharge cavity 113. When a sound wave matching the silencing length is transmitted to the inlet end of the silencing channel, due to the acoustic impedance mismatch caused by the presence of the silencing channel, most of the sound wave is reflected, and a portion is converted into heat energy and absorbed due to damping. Thus, only a small portion of the sound wave can continue to propagate forward, thereby achieving silencing. When the silencing length is different, more frequency bands of sound waves can be absorbed, thereby improving the silencing effect.

[0053] It should be understood that although the wall of the discharge cavity 113 in this application is provided with eight holes, any number of holes and the number of corresponding adjusting pistons are within the protection scope of this application.

[0054] Figure 11 shows a cross-sectional view of the fifth embodiment of the noise reduction structure. As shown in Figure 11, a square hole 1122 is provided on the screw compressor housing 101. The width of the hole 1122 is approximately the sum of the diameters of the eight holes 122 shown in the embodiment of Figure 2. The adjustment cavity 1104 of the adjustment box 132 communicates with the hole 1122, forming a continuous channel. The adjustment piston 1142 is disposed in the continuous channel and is able to move in the continuous channel. At this time, the noise reduction channel 1188 is formed from the inlet end of the hole 1122 to the end face of the adjustment piston 1142. When the adjustment piston 1142 moves in the continuous channel, different noise reduction lengths can be formed.

[0055] A plate 1144 is also provided in the discharge cavity 113. The plate 1144 has several perforations 1110. The plate 1144 covers the holes 1122, thereby covering the entrance end of the silencing channel 1188, so that sound waves can enter the channel formed by the regulating cavity 1104 and the holes 1122 through the perforations 1110. The perforations 1110 on the plate 1144 and the channel form a silencing structure. When a sound wave matching the silencing length is transmitted to the vicinity of the perforations 1110, due to the acoustic impedance mismatch caused by the existence of the silencing channel, most of the sound waves are reflected, and a portion is converted into heat energy and absorbed due to damping, thus allowing only a small portion of the sound waves to continue propagating forward, thereby achieving silencing.

[0056] Figure 12 shows a cross-sectional view of a sixth embodiment of the silencing structure. The embodiment shown in Figure 12 is largely the same as the embodiment shown in Figure 11, and will not be described again here. The difference from the embodiment shown in Figure 11 is that the discharge cavity 113 of the embodiment shown in Figure 12 is provided with two plates 1242 and 1244. Each of the two plates 1242 and 1244 has several perforations. The two plates 1242 and 1244 can move relative to each other, thereby changing the alignment area of ​​the perforations. The aligned portion of the two plates 1242 and 1244 forms an additional silencing channel, allowing the discharge cavity 113 to communicate with the silencing channel 1188 through the perforations. By changing the area of ​​the additional silencing channel, the pulsating wavelength of the main silencing effect of this silencing structure can be changed, thereby matching and reducing the peak energy under different operating conditions.

[0057] It should be noted that although two plates are shown in this application, any number of plates are within the scope of protection of this application, as long as an additional sound-absorbing channel can be formed between the plates.

[0058] Thus, this application provides a screw compressor in which the length of the silencer channel can be automatically adjusted according to the operating conditions of the screw compressor (e.g., operating frequency, exhaust temperature, exhaust pressure, etc.), thereby effectively reducing the peak energy of exhaust pulsation under different operating conditions and reducing noise.

[0059] Furthermore, the silencing structure of this application forms part of a silencing channel by providing holes on the inner wall, thereby making the silencing structure small in size and compact in layout. This silencing structure does not increase the flow resistance of airflow and is easy to manufacture.

[0060] Although only some features of this application have been illustrated and described herein, various modifications and variations can be made by those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all such modifications and variations that fall within the essential spirit of this application. [Simplified Explanation of the Diagram]

[0062] The features and advantages of this application can be better understood by reading the following detailed description with reference to the accompanying drawings, in which the same reference numerals denote the same parts throughout the drawings, wherein: FIG1A is a perspective view of a screw compressor according to an embodiment of the present application, viewed from front to back; FIG1B is a cross-sectional view of the screw compressor shown in FIG1A, viewed from back to front along the length direction of the screw compressor; FIG1C is a cross-sectional view of the screw compressor shown in FIG1A, cut along the width direction of the screw compressor to the discharge chamber of the screw compressor; FIG2 is a cross-sectional view of a first embodiment of the silencing structure shown in FIG1A; FIG3 is a partial system diagram of a refrigeration system using the screw compressor of the present application; FIG4 is a flow path diagram of the lubricant in the refrigeration system when the adjusting slider is moved upward; FIG5 is a flow path diagram of the lubricant in the refrigeration system when the adjusting slider is moved downward; FIG6 is a schematic diagram of the principle of controlling the movement of the adjusting slider and the adjusting piston; FIG7 is a schematic diagram of another embodiment of the drive mechanism for driving the adjusting slider and eight adjusting pistons; FIG8 is a cross-sectional view of a second embodiment of the silencing structure; FIG9 is a cross-sectional view of a third embodiment of the silencing structure. Figure 10 is a cross-sectional view of the fourth embodiment of the noise reduction structure; Figure 11 is a cross-sectional view of the fifth embodiment of the noise reduction structure; Figure 12 is a cross-sectional view of the sixth embodiment of the noise reduction structure.

Claims

1. A screw compressor, the screw compressor comprising: Screw compressor housing; Discharge cavity The discharge cavity is defined by at least a portion of the screw compressor housing, the at least a portion of the screw compressor housing defining the discharge cavity forms the wall of the discharge cavity, and the wall of the discharge cavity is provided with at least two holes; at least two adjusting pistons, each of the at least two adjusting pistons being configured to insert into and move within one of the at least two holes; The compressor includes at least two silencer channels, each formed by the at least two holes and the at least two adjusting pistons, and the at least two silencer channels are in fluid communication with the discharge cavity; wherein, the position of each of the at least two adjusting pistons in the individual hole determines the silencer length of an individual silencer channel; wherein the screw compressor further includes an adjusting slider, and the at least two adjusting pistons are connected to the adjusting slider; and wherein the adjusting slider and the at least two adjusting pistons are configured such that when the adjusting slider reciprocates relative to the screw compressor housing, each of the at least two adjusting pistons can reciprocate within the individual silencer channel, thereby changing the silencer length of each of the at least two silencer channels.

2. The screw compressor as claimed in claim 1, wherein: The at least two adjusting pistons are capable of reciprocating independently relative to the screw compressor housing.

3. The screw compressor as claimed in claim 1, wherein: The at least two adjusting pistons are configured such that at any given moment during the reciprocating movement of the at least two adjusting pistons relative to the screw compressor housing, each of the at least two silencing channels has a different silencing length.

4. The screw compressor as claimed in claim 1, wherein: Each of the at least two orifices has an inlet end and a distal end opposite to the inlet end, and is configured to receive an individual adjusting piston from the distal end of the at least two adjusting pistons; The distance between the top of one of the at least two adjusting pistons and the inlet end is the silencing length.

5. The screw compressor as claimed in claim 1, wherein: Each of the at least two orifices has an inlet end and a distal end opposite to the inlet end, and is configured to receive an individual adjusting piston from the distal end of the at least two adjusting pistons; And each of the at least two adjusting pistons has a recess extending from one end of the individual adjusting piston to the other end, and the distance between the bottom of the recess and the inlet end is the silencing length.

6. The screw compressor as claimed in claim 1, wherein: The screw compressor further includes an adjustment box, which is arranged on the outside of the screw compressor housing and defines an adjustment cavity; the adjustment slider is disposed in the adjustment box and divides the adjustment cavity into a first receiving portion and a second receiving portion, the first receiving portion being formed on the side of the adjustment slider near the screw compressor housing, and the second receiving portion being formed between the adjustment box and the adjustment slider.

7. A screw compressor, the screw compressor comprising: Screw compressor housing; Discharge cavity The discharge cavity is defined by at least a portion of the screw compressor housing, and the at least a portion of the screw compressor housing defining the discharge cavity forms the wall of the discharge cavity, and the wall of the discharge cavity is provided with at least two holes; An adjustment box is disposed on the outside of the screw compressor housing and defines an adjustment cavity, the adjustment cavity forming at least two continuous channels with the at least two holes; At least two adjusting pistons, each of the at least two adjusting pistons being configured to insert into and move within one of the at least two consecutive channels; And at least two silencing channels, the at least two silencing channels being formed by the at least two holes, the at least two adjusting pistons and the adjusting box, the at least two silencing channels being in fluid communication with the discharge cavity; wherein, the position of the at least two adjusting pistons in the at least two holes and the adjusting cavity determines the silencing length of the at least two silencing channels.

8. The screw compressor as claimed in claim 7, wherein: The screw compressor further includes at least one plate arranged in the discharge cavity and covering the at least two holes; and the at least one plate is provided with a plurality of perforations, which are arranged to arrange the discharge cavity in fluid communication with the at least two silencers.

9. The screw compressor as claimed in claim 7, comprising an adjusting slider, wherein: The adjusting slider is disposed in the adjusting box, and the adjusting cavity is divided into a first receiving part and a second receiving part. The first receiving part is formed on the side of the adjusting slider near the screw compressor housing, and the second receiving part is formed between the adjusting box and the adjusting slider.

10. The screw compressor as claimed in claim 7, wherein: The at least two adjusting pistons are configured such that at any given moment during the reciprocating movement of the at least two adjusting pistons relative to the screw compressor housing, the silencing length of each of the at least two silencing channels is different.

11. A refrigeration system, the refrigeration system comprising: The screw compressor according to claim 9; The system includes a lubricant circuit connected to the screw compressor; wherein the second housing is disconnectably connected to the lubricant circuit and disconnectably connected to the inlet of the screw compressor; and wherein the refrigeration system is configured to supply lubricant from the lubricant circuit to the second housing such that each of the at least two adjusting pistons moves toward an individual inlet end of each of the at least two orifices, and is configured to introduce lubricant from the second housing into the inlet of the screw compressor such that each of the at least two adjusting pistons moves away from the individual inlet end.

12. A screw compressor, comprising: a screw compressor housing; a discharge chamber defined by at least a portion of the screw compressor housing, the at least a portion of the screw compressor housing defining the discharge chamber forming a wall of the discharge chamber, and the wall of the discharge chamber having at least two holes; at least two adjusting pistons, each of the at least two adjusting pistons being configured to insert into and move within one of the at least two holes; and at least two silencing channels, the at least two silencing channels being formed by the at least two holes and the at least two adjusting pistons, and the at least two silencing channels being in fluid communication with the discharge chamber; wherein, The individual position of each of the at least two adjusting pistons in the at least two holes determines the silencing length of an individual silencing channel in the at least two silencing channels; and wherein the at least two adjusting pistons can move independently relative to the screw compressor housing to reciprocate, thereby changing the silencing length of each of the at least two silencing channels.

13. A screw compressor, comprising: a screw compressor housing; a discharge chamber defined by at least a portion of the screw compressor housing, the at least a portion of the screw compressor housing defining the discharge chamber forming a wall of the discharge chamber, and the wall of the discharge chamber having at least two holes; at least two adjusting pistons, each of the at least two adjusting pistons being configured to insert into and move within an individual of the at least two holes; and at least two silencing channels, the at least two silencing channels being formed by the at least two holes and the at least two adjusting pistons, and the at least two silencing channels being in fluid communication with the discharge chamber; wherein, The positions of the at least two adjusting pistons in the at least two holes determine the silencing length of the at least two silencing channels; wherein each of the at least two holes has an inlet end and a distal end opposite to the inlet end, and each of the at least two adjusting pistons is assembled to be inserted into an individual hole of the at least two holes from the distal end; and wherein each of the at least two adjusting pistons has a recess extending from one end of its end face toward the other end, the distance between the bottom of the recess and the inlet end being the silencing length.

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