Screw rod driving type compressor and air volume adjusting method thereof

Abstract

The invention discloses a screw rod driving type compressor and an air quantity adjusting method thereof, and belongs to the technical field of compressors, the screw rod driving type compressor comprises an air cylinder shell, a screw rod driving mechanism and a screw rod driving mechanism, the air cylinder shell is provided with a compression cavity, a containing cavity, an overflowing channel and a through hole communicating with the compression cavity and the containing cavity, the containing cavity communicates with the overflowing channel, and the overflowing channel communicates with an air inlet channel of the compressor; the valve rod assembly comprises a baffle part, a valve body part and a lead screw part, the baffle part is arranged in the containing cavity and divides the containing cavity into a first cavity body and a second cavity body, the first cavity body and the second cavity body are arranged at intervals in the length direction, and the first cavity body communicates with the overflowing channel. The screw rod part is arranged to drive the valve body part to move, so that the valve body part moves in the length direction, the covering area of the valve body part to the through hole can be adjusted according to needs, the opening degree of the through hole is controlled, the amount of gas entering the first cavity from the compression cavity is adjusted, impurities cannot be guided into the compression cavity in the process, and the compression efficiency is improved. And compressed gas in the compression cavity is ensured to be clean.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressors, in particular to a lead screw driven compressor and a method for adjusting the air volume of the lead screw driven compressor. BACKGROUND

[0002] When the air volume of the compressor is adjusted, the internal slide valve is driven by hydraulic pressure or air pressure. For an oil-free screw compressor with extremely strict requirements for the purity of the compressed medium, hydraulic drive or air pressure drive of the slide valve will cause impurities to enter the compression chamber, thereby polluting the medium in the compression chamber. SUMMARY

[0003] The embodiments of the present application provide a lead screw driven compressor and a method for adjusting the air volume of the lead screw driven compressor to solve the technical problem that impurities enter the compression chamber when the air volume of the compressor is adjusted.

[0004] In order to achieve the above-mentioned purpose, according to the first aspect of the present application, a lead screw driven compressor is provided, comprising: a cylinder housing having a compression chamber, a containing chamber, a flow passage, and a through hole communicating the compression chamber and the containing chamber, the containing chamber being in communication with the flow passage, and the flow passage being in communication with an air inlet passage of the compressor; a valve rod assembly comprising a baffle part, a valve body part, and a lead screw part, the baffle part being arranged in the containing chamber to divide the containing chamber into a first chamber and a second chamber, the first chamber and the second chamber being arranged in a length direction, the first chamber being in communication with the flow passage, and the first chamber being in communication with the compression chamber through the through hole, the valve body part being arranged in the first chamber, the lead screw part being arranged in the containing chamber and penetrating the baffle part and the valve body part in the length direction, the lead screw part being in transmission connection with the valve body part, and the lead screw part being configured to drive the valve body part to move in the length direction to adjust the coverage area of the valve body part to the through hole.

[0005] Optionally, the compression chamber comprises a first compression chamber and a second compression chamber in communication, the number of the through holes is two, the two through holes are arranged in a width direction and are arranged on the inner wall of the first compression chamber and the inner wall of the second compression chamber respectively, the first compression chamber is in communication with the first chamber through one of the through holes, and the second compression chamber is in communication with the first chamber through the other through hole.

[0006] Optionally, the containing chamber has a first inner wall surface and a second inner wall surface connected, one of the two through holes is formed on the first inner wall surface, and the other is formed on the second inner wall surface; The first contact surface is in sliding connection with the first inner wall surface and covers at least a part of the through hole on the first inner wall surface, and the second contact surface is in sliding connection with the second inner wall surface and covers at least a part of the through hole on the second inner wall surface.

[0007] Optionally, the number of the flow channels is two, and the two flow channels are arranged at intervals along the width direction and are in communication with the air inlet channel of the compressor.

[0008] Optionally, a female rotor is arranged in the first compression chamber, a male rotor is arranged in the second compression chamber, the center distance between the female rotor and the male rotor is H1, and the size of the valve body part in the width direction is H2, and the following condition is met: 0.5≤H2 / H1≤0.7.

[0009] Optionally, the cylinder shell has a guide groove in communication with the accommodating cavity, the guide groove extends along the length direction, and the valve body part comprises a guide block embedded in the guide groove.

[0010] Optionally, the surface of the valve body part is provided with a coating structure, the friction coefficient of the coating structure is μ, and the following condition is met: μ≤0.2.

[0011] Optionally, the baffle part comprises: a main body arranged in the accommodating cavity and separating the accommodating cavity into the first cavity and the second cavity, the outer periphery of the main body having a sealing groove; a sealing ring arranged in the sealing groove and sealingly connecting the main body and the inner wall of the accommodating cavity.

[0012] Optionally, one end of the screw rod part is arranged in the second cavity, the bottom of the cylinder shell has a connecting hole in communication with the second cavity, and the connecting hole is used for embedding a driving member into the second cavity and rotating one end of the screw rod part.

[0013] Optionally, one end of the screw rod part is a multi-prism structure.

[0014] Optionally, the surface of the screw rod part is provided with a thread, the thread is a trapezoidal thread, the thread angle of the trapezoidal thread is α, and the following condition is met: 30°≤α≤35°.

[0015] Optionally, the cross-sectional area of the flow channel is A, and the cross-sectional area of the through hole is B, and the following condition is met: 1.2≤A / B≤2.

[0016] Optionally, the size of the through hole in the length direction is L1, and the size of the compression chamber in the length direction is L2, and the following condition is met: 0.2≤L1 / L2≤0.3.

[0017] Optionally, the intake volume of the intake passage is C, and the discharge volume of the compressor is M, and 0.5≤M / C≤1 is satisfied.

[0018] According to a second aspect of the present application, a method for adjusting the gas volume of a screw-driven compressor is provided, which is applied to any one of the above-mentioned screw-driven compressors, and the method comprises: determining a target coverage area of the valve body part to the through hole according to the target gas volume of the compressor; rotating one end of the screw rod part located in the second cavity to drive the valve body part to move in the length direction in the first cavity; the relative position of the valve body part to the through hole changes when the valve body part slides, and then the actual coverage area of the valve body part to the through hole is adjusted until the actual coverage area is consistent with the target coverage area; the part of the gas in the compression cavity enters the first cavity through the uncovered area of the through hole, and then flows back to the intake passage of the compressor through the flow passage, so as to realize the adjustment of the gas volume of the compressor.

[0019] The screw-driven compressor of the embodiment of the present application comprises: a cylinder shell having a compression cavity, a containing cavity, a flow passage, and a through hole communicating the compression cavity and the containing cavity, the containing cavity being communicated with the flow passage, and the flow passage being communicated with the intake passage of the compressor; a valve rod assembly comprising a baffle part, a valve body part, and a screw rod part, the baffle part being arranged in the containing cavity to separate the containing cavity into a first cavity and a second cavity, the first cavity and the second cavity being arranged in the length direction, the first cavity being communicated with the flow passage, and the first cavity being communicated with the compression cavity through the through hole, the valve body part being arranged in the first cavity, the screw rod part being arranged in the containing cavity and penetrating the baffle part and the valve body part in the length direction, the screw rod part being in transmission connection with the valve body part, and the screw rod part being configured to drive the valve body part to move in the length direction to adjust the coverage area of the valve body part to the through hole. By arranging the screw rod part to drive the valve body part to move, the valve body part can move in the length direction, the coverage area of the valve body part to the through hole can be adjusted as needed, the opening of the through hole can be controlled, and the amount of gas entering the first cavity from the compression cavity can be adjusted. This process does not introduce impurities into the compression cavity, and the compressed gas in the compression cavity is ensured to be clean. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0021] For a more complete understanding of the present application and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals indicate like parts:

[0022] Figure 1 is a front view cross-section of a screw-driven compressor provided in an exemplary embodiment of the present disclosure; Figure 2 is a perspective view of a cylinder housing provided in an exemplary embodiment of the present disclosure; Figure 3 is a cross-section view of a connection of a cylinder housing and a valve stem assembly provided in an exemplary embodiment of the present disclosure; Figure 4 is a partial structural schematic view of a containing cavity provided in an exemplary embodiment of the present disclosure; Figure 5 is a perspective view of a valve body portion provided in an exemplary embodiment of the present disclosure; Figure 6 is a partial structural schematic view of a compression cavity provided in an exemplary embodiment of the present disclosure; Figure 7 is a perspective view of a screw rod portion provided in an exemplary embodiment of the present disclosure; Figure 8 is a perspective view of a baffle portion provided in an exemplary embodiment of the present disclosure; Figure 9 is a cross-section view of a cylinder housing provided in an exemplary embodiment of the present disclosure.

[0023] BRIEF DESCRIPTION OF DRAWINGS 10 - cylinder housing; 11 - compression cavity; 111 - first compression chamber; 112 - second compression chamber; 12 - containing cavity; 121 - first cavity; 122 - second cavity; 123 - first inner wall surface; 124 - second inner wall surface; 13 - flow passage; 14 - through hole; 15 - female rotor; 16 - male rotor; 17 - guide groove; 18 - connection hole; 20 - valve stem assembly; 21 - baffle portion; 211 - main body; 212 - sealing groove; 213 - sealing ring; 22 - valve body portion; 221 - first contact surface; 222 - second contact surface; 223 - guide block; 224 - coating structure; 23 - screw rod portion; 30 - compressor; 31 - intake passage; X - length direction; Y - width direction. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0025] In the technical development history of screw compressor, the gas capacity regulation ability has been one of the core indicators to measure the technical advancement and energy efficiency level. The traditional regulation methods such as frequency regulation and circulation backflow regulation have mature technology and simple structure, but all have the following problems: the frequency regulation has high investment cost and high maintenance cost, and the compressor efficiency is low during low-speed operation; the circulation backflow regulation wastes energy, and the slide valve regulation, as the most mature and mainstream technology in the oil-injected screw compressor, continuously changes the effective working length of the compressor by the axial movement of the slide valve in the rotor cavity, thereby realizing stepless and smooth regulation of the exhaust capacity between 100% and part load, and effectively reducing the power consumption under part load, which shows its excellent energy-saving potential and operation flexibility. However, when the slide valve is applied to the oil-free screw compressor field which has higher technical threshold and extremely strict requirements for medium purity, it has the following problems in driving and sealing: in the oil-injected machine, the lubricating oil itself as a sealing, cooling and lubricating medium provides a relatively "tolerant" inclusive environment for the driving mechanism (usually hydraulic or pneumatic) of the slide valve, and even if there is a trace of leakage of the driving element, it will not pollute the compressed medium because of mixing with the lubricating oil, but in the oil-free environment, any oil molecule leakage from the hydraulic driver or impurities carried by the air quality of the pneumatic driver will directly contaminate the absolutely clean compressed gas (such as steam, process gas, special gas, food or medical gas), resulting in the failure of the entire oil-free design. Secondly, during the operation of the oil-free screw compressor, there is no oil film lubrication and cooling between the rotor and the shell, and between the rotors, which are in dry friction or rely on Teflon and other non-metallic coatings for self-lubrication, and the working temperature is much higher than that of the oil-injected machine, which makes it extremely difficult to control the thermal expansion of the traditional slide valve and the shell gap at high temperature. If it is too tight, it will easily cause "stuck" or abnormal wear, which will pollute the gas and damage the main machine, and if it is too loose, it will cause a sharp increase in internal leakage, which will seriously reduce the volumetric efficiency and energy efficiency of the compressor; in addition, the friction force required to drive the slide valve increases significantly under high temperature and no lubrication conditions, which requires more stringent driving force, and the traditional hydraulic or pneumatic drive is difficult to meet the requirements in terms of response accuracy, position control stability and pollution risk prevention.

[0026] Please refer to Figure 1 , Figure 2 and Figure 3 , the embodiment of the present application provides a lead screw driven compressor, which comprises a cylinder shell 10 and a valve rod assembly 20.

[0027] The cylinder housing 10 has a compression cavity 11, a containing cavity 12, a flow passage 13, and a through hole 14 connecting the compression cavity 11 and the containing cavity 12, the containing cavity 12 is communicated with the flow passage 13, and the flow passage 13 is communicated with an inlet passage 31 of a compressor 30. The valve rod assembly 20 includes a baffle part 21, a valve body part 22, and a screw rod part 23, the baffle part 21 is arranged in the containing cavity 12, and divides the containing cavity 12 into a first cavity 121 and a second cavity 122, the first cavity 121 and the second cavity 122 are arranged in a length direction X, the first cavity 121 is communicated with the flow passage 13, and the first cavity 121 is communicated with the compression cavity 11 through the through hole 14, the valve body part 22 is arranged in the first cavity 121, the screw rod part 23 is arranged in the containing cavity 12 and penetrates the baffle part 21 and the valve body part 22 in the length direction X, the screw rod part 23 is drivingly connected with the valve body part 22, and the screw rod part 23 is configured to drive the valve body part 22 to move in the length direction X to adjust the covering area of the valve body part 22 to the through hole 14. The length direction X is a direction in which the cylinder housing 10 has a length.

[0028] It can be understood that the compression cavity 11 containing the rotor is arranged in the cylinder housing 10, the inlet passage 31 delivers medium to the inside of the compression cavity 11, so that the medium is compressed in the compression cavity 11, and the medium can be steam, process gas, special gas, food or medical gas, and other gases with high cleanliness requirements. The compression cavity 11 is communicated with the containing cavity 12 through the through hole 14, when it is necessary to adjust the amount of gas discharged by the compressor 30, part of the medium in the compression cavity 11 can be delivered to the containing cavity 12 through the through hole 14, and then delivered to the inlet passage 31 through the flow passage 13 communicated with the containing cavity 12, so that the part of the medium can re-enter the compression cavity 11 through the inlet passage 31 and be utilized.

[0029] The valve stem assembly 20 is arranged inside the accommodating cavity 12, the baffle part 21 in the valve stem assembly 20 is arranged inside the accommodating cavity 12 and is fixedly connected with the inner wall of the accommodating cavity 12 through a bolt, and the accommodating cavity 12 is divided into the first cavity 121 and the second cavity 122 through the baffle part 21. The valve body part 22 is arranged inside the first cavity 121 and can slide along the length direction X, and the upper surface of the valve body part 22 is attached to the upper surface of the inner wall of the accommodating cavity 12, and when the valve body part 22 moves, the upper surface of the valve body part 22 will slide along the upper surface of the inner wall of the accommodating cavity 12. The opening of the through hole 14 is arranged on the upper surface of the inner wall of the accommodating cavity 12, and when the valve body part 22 moves along the length direction X, the opening of the through hole 14 will be covered, and the area of the covering will change with the movement of the valve body part 22. That is, by moving the valve body part 22, the opening of the through hole 14 can be adjusted, so that the flow of the medium from the compression cavity 11 into the first cavity 121 through the through hole 14 is adjusted, and the purpose of adjusting the air volume of the compressor 30 is achieved. The through hole is arranged on the baffle part 21 for the lead screw part 23 to pass through, the lead screw part 23 passes through the through hole, a part of which is located in the first cavity 121 and a part of which is located in the second cavity 122, and the part of the lead screw part 23 located in the first cavity 121 is arranged in the valve body part 22 and movably connected with the inner wall of the first cavity 121, so that the lead screw part 23 can only rotate along the circumference direction and cannot move in the axial and radial directions. The lead screw part 23 is in transmission connection with the valve body part 22 through threads, and rotating the part of the lead screw part 23 in the second cavity 122 can drive the valve body part 22 to move along the length direction X under the action of the threads, so as to adjust the covering area of the valve body part 22 to the through hole 14, and adjust the flow of the medium through the through hole 14.

[0030] The structure does not need to move the valve body part 22 along the length direction X through hydraulic drive or pneumatic drive, so when the air volume is adjusted, the medium re-entering the compression cavity 11 through the first cavity 121 will not be contaminated by impurities such as lubricating oil, so that the cleanliness of the medium in the compression cavity 11 can be ensured, and the risk of contamination of the medium is reduced.

[0031] Please refer to Figure 2 , in combination with the above embodiments, in some embodiments, the compression cavity 11 includes a first compression chamber 111 and a second compression chamber 112 connected in communication, the number of through holes 14 is two, the two through holes 14 are arranged in the width direction Y and are arranged on the inner walls of the first compression chamber 111 and the second compression chamber 112 respectively, the first compression chamber 111 is communicated with the first cavity 121 through one of the through holes 14, and the second compression chamber 112 is communicated with the first cavity 121 through the other through hole 14.

[0032] It can be understood that the first compression chamber 111 is provided with a female rotor 15, and the second compression chamber 112 is provided with a male rotor 16, and the two rotors compress the medium in the respective compression chambers. In order to facilitate the medium in the first compression chamber 111 and the medium in the second compression chamber 112 to quickly pass through the through hole 14 into the first cavity 121 when the air volume of the compressor 30 is adjusted, a through hole 14 communicating with the first cavity 121 is arranged on the inner wall of the first compression chamber 111, and a through hole 14 communicating with the first cavity 121 is also arranged on the inner wall of the second compression chamber 112. The medium in the corresponding compression chamber can directly pass through the through hole 14 on the respective inner wall into the first cavity 121, thereby shortening the flow path of the medium, increasing the flow area, and improving the efficiency of air volume adjustment of the compressor 30. The through hole 14 on the inner wall of each compression chamber can be composed of a plurality of sub-holes, and the plurality of sub-holes can be arranged at intervals along the length direction X, thereby further improving the efficiency of air volume adjustment.

[0033] Please refer to Figure 2 、 Figure 4 and Figure 5 , in combination with the above embodiments, in some embodiments, the accommodation cavity 12 has a first inner wall surface 123 and a second inner wall surface 124 connected thereto, one of the two through holes 14 is formed on the first inner wall surface 123, and the other is formed on the second inner wall surface 124. The valve body portion 22 includes a first contact surface 221 and a second contact surface 222, the first contact surface 221 is in sliding connection with the first inner wall surface 123, and is used to cover at least a part of the through hole 14 on the first inner wall surface 123, and the second contact surface 222 is in sliding connection with the second inner wall surface 124, and is used to cover at least a part of the through hole 14 on the second inner wall surface 124.

[0034] It can be understood that, as shown in Figure 4 , the inner wall of the accommodation cavity 12 has a first inner wall surface 123 and a second inner wall surface 124 connected thereto, and the two through holes 14 are respectively formed on the first inner wall surface 123 and the second inner wall surface 124. Preferably, the first inner wall surface 123 and the second inner wall surface 124 are arc surfaces. The top of the valve body portion 22 has a first contact surface 221 adapted to the first inner wall surface 123, and also has a second contact surface 222 adapted to the second inner wall surface 124, and the first contact surface 221 and the second contact surface 222 are also arc surfaces, facilitating the two to be closely attached to the first inner wall surface 123 and the second inner wall surface 124 respectively. When the valve body portion 22 moves along the length direction X, the opening size of the through hole 14 on the first inner wall surface 123 can be adjusted by the first contact surface 221, and the opening size of the through hole 14 on the second inner wall surface 124 can be adjusted by the second contact surface 222, thereby realizing the effect of air volume adjustment, and at the same time, when the first contact surface 221 and the second contact surface 222 completely cover the corresponding through hole 14, the medium in the compression chamber 11 can be prevented from entering the inside of the first cavity 121.

[0035] Referring to Figure 2 , in combination with the above embodiments, in some embodiments, the number of overflow passages 13 is two, and the two overflow passages 13 are arranged along the width direction Y and are in communication with the intake passage 31 of the compressor 30. The width direction Y is the direction in which the width of the cylinder housing 10 is located, and the width direction Y intersects the length direction X, and preferably, the width direction Y and the length direction X are perpendicular to each other.

[0036] It can be understood that, in order to facilitate the medium entering the first cavity 121 through the two through holes 14, the medium can quickly enter the intake passage 31 of the compressor 30 through the overflow passage 13, so the number of overflow passages 13 is also set to two, and the two overflow passages 13 are arranged along the width direction Y and are respectively arranged on both sides of the containing cavity 12. One of the overflow passages 13 is closer to the through hole 14 on the first inner wall surface 123, and the medium entering the first cavity 121 through the through hole 14 can be preferentially delivered to the intake passage 31 through the closest overflow passage 13. The other overflow passage 13 is closer to the through hole 14 on the second inner wall surface 124, and the medium entering the first cavity 121 through the through hole 14 can be preferentially delivered to the intake passage 31 through the closest other overflow passage 13. Through this structural arrangement, the medium entering the first cavity 121 can be quickly discharged, improving the efficiency of the exhaust, and at the same time, it can also avoid the pressure in the first cavity 121 being too large, causing damage to the inner wall of the first cavity 121 and the valve stem assembly 20.

[0037] Referring to Figure 6 , in combination with the above embodiments, in some embodiments, the first compression chamber 111 is provided with a female rotor 15, and the second compression chamber 112 is provided with a male rotor 16, the center distance between the female rotor 15 and the male rotor 16 is H1, and the size of the valve body portion 22 in the width direction Y is H2, and it is satisfied that 0.5≤H2 / H1≤0.7.

[0038] It can be understood that the ratio between the size of the valve body portion 22 in the width direction Y and the center distance between the female rotor 15 and the male rotor 16 can be any value in 0.5, 0.55, 0.6, 0.65, 0.7, or a range value between two values. When the value of H2 / H1 is greater than 0.7, the width of the valve body portion 22 is too large, which will cause the cross-sectional area of the overflow passage 13 to decrease, thereby increasing the gas flow rate through the overflow passage 13, which will produce larger airflow noise and vibration. When the value of H2 / H1 is less than 0.5, the width of the valve body portion 22 is too small, which will correspondingly cause the cross-sectional area of the through hole 14 to decrease, the gas flow rate through the through hole 14 to decrease, and the gas backflow adjustment range to decrease.

[0039] It can be understood that the ratio of the size H2 of the valve body part 22 in the width direction Y to the center distance H1 between the female rotor 15 and the male rotor 16 is between 0.5 and 0.7, and can be any one of 0.5, 0.53, 0.56, 0.59, 0.62, 0.65, 0.68, 0.7 or a range value between two values.

[0040] Please refer to Figure 2 , Figure 3 , Figure 4 , and Figure 5 , in combination with the above embodiments, in some embodiments, the cylinder housing 10 has a guide groove 17 in communication with the accommodation cavity 12, the guide groove 17 extends along the length direction X, and the valve body part 22 includes a guide block 223 embedded into the guide groove 17.

[0041] It can be understood that the guide groove 17 is formed on the bottom wall of the accommodation cavity 12, and the guide block 223 is arranged at the bottom of the valve body part 22 and can be embedded into the inside of the guide groove 17, which can guide the movement of the valve body part 22 and ensure the stability of the valve body part 22 during movement, avoiding the valve body part 22 from shaking in the direction perpendicular to the length direction X under the driving of the screw rod part 23. The length of the guide groove 17 can be set as needed. When the valve body part 22 moves away from the baffle part 21 until the guide block 223 abuts against the inner wall of one end of the guide groove 17, the valve body part 22 cannot move away from the baffle part 21 any more. At this time, the valve body part 22 can completely cover the through hole 14, so that the medium in the compression cavity 11 cannot enter the first cavity 121 through the through hole 14. This structure can position the valve body part 22, and when the valve body part 22 moves to this state, it means that the valve body part 22 completely covers the through hole 14.

[0042] Please refer to Figure 5 , in combination with the above embodiments, in some embodiments, the surface of the valve body part 22 is provided with a coating structure 224, and the friction coefficient of the coating structure 224 is μ, which satisfies: μ≤0.2.

[0043] It can be understood that the coating structure 224 is arranged on the surface of the valve body part 22, which can be arranged on the surface of the valve body part 22 in contact with the inner wall of the first cavity 121, or on all surfaces of the valve body part 22. The friction coefficient of the coating structure 224 is less than or equal to 0.2, which can be a polytetrafluoroethylene coating, a fluoropolymer composite coating, etc. The friction between the valve body part 22 and the inner wall of the first cavity 121 can be reduced when the valve body part 22 moves, facilitating the movement of the valve body part 22.

[0044] Please refer to Figure 8In combination with the above embodiments, in some embodiments, the baffle part 21 comprises a main body 211 and a sealing ring 213.

[0045] The main body 211 is arranged in the accommodating cavity 12, and divides the accommodating cavity 12 into a first cavity 121 and a second cavity 122. The outer periphery of the main body 211 has a sealing groove 212. The sealing ring 213 is arranged in the sealing groove 212, and is used to seal and connect the main body 211 and the inner wall of the accommodating cavity 12.

[0046] It can be understood that when the main body 211 of the baffle part 21 is arranged in the accommodating cavity 12, the sealing groove 212 is arranged around the outer periphery of the main body 211. The sealing ring 213 can be arranged in the sealing groove 212. The sealing ring 213 protrudes from the sealing groove 212 and abuts against the inner wall of the accommodating cavity 12, thereby improving the sealing performance of the connection between the main body 211 and the inner wall of the accommodating cavity 12, and preventing the medium in the first cavity 121 from leaking into the second cavity 122. The number of the sealing groove 212 and the sealing ring 213 can be set as required.

[0047] Please refer to Figure 3 and Figure 7 In combination with the above embodiments, in some embodiments, one end of the screw rod part 23 is arranged in the second cavity 122. The bottom of the cylinder shell 10 has a connecting hole 18 that is in communication with the second cavity 122. The connecting hole 18 is used for embedding a driving member into the second cavity 122 and rotating one end of the screw rod part 23.

[0048] It can be understood that the second cavity 122 is in communication with the connecting hole 18 at the bottom of the cylinder shell 10. The connecting hole 18 is in communication with the external environment. The driving member such as a wrench can be directly embedded into the second cavity 122 through the connecting hole 18 and connected to one end of the screw rod part 23 in the second cavity 122. The screw rod part 23 is directly rotated by the driving member, thereby driving the valve body part 22 to move. This structure can manually adjust the position of the valve body part 22, and the driving is reliable, efficient and energy-saving.

[0049] Please refer to Figure 7 In combination with the above embodiments, in some embodiments, one end of the screw rod part 23 is in a polygonal structure, such as a quadrangular prism or a hexagonal prism structure, which facilitates the rotation of the screw rod part 23 by a wrench or the like.

[0050] Please refer to Figure 7 In combination with the above embodiments, in some embodiments, the surface of the screw rod part 23 is provided with threads. The tooth profile of the thread is a trapezoidal tooth, and the tooth profile angle of the trapezoidal tooth is α, which satisfies: 30°≤α≤35°.

[0051] It can be understood that the thread is selected as a trapezoidal tooth design with a tooth angle of 30° to 35°. The trapezoidal tooth profile has the characteristics of wide load bearing surface and uniform stress. It can not only reduce the idle stroke and jam in the transmission process, so that the sliding speed of the valve body part 22 can be accurately controlled by the rotation speed of the screw rod part 23, but also can generate enough static friction on the meshing surface by matching the helix angle and equivalent friction angle of the tooth angle, so that the screw rod part 23 will not displace when it stops sliding, realizing reliable self-locking, and well adapting to the use requirements of the valve body part 22 for motion speed control and stopping stability. If the tooth angle is too large, the self-locking performance will be reduced, and if the tooth angle is too small, the speed of the valve body part 22 moving when the screw rod part 23 rotates will be slower, and the working efficiency will be reduced.

[0052] Please refer to Figure 2 , in combination with the above embodiments, in some embodiments, the cross-sectional area of the overflow passage 13 is A, and the cross-sectional area of the through hole 14 is B, which satisfies: 1.2≤A / B≤2.

[0053] It can be understood that the overflow passage 13 needs to meet the passage of all backflow gas and entrained liquid, and the overflow area needs to be larger than the cross-sectional area of the through hole 14. When the ratio of the cross-sectional area of the overflow passage 13 to the cross-sectional area of the through hole 14 is less than 1.2, the gas-liquid flow rate in the overflow passage 13 will increase, which will increase the noise and vibration amplitude during operation. When the ratio of the cross-sectional area of the overflow passage 13 to the cross-sectional area of the through hole 14 is greater than 2, the amount of material removed at the bottom of the cylinder shell 10 will increase, which will reduce the strength of the compressor 30 shell.

[0054] Please refer to Figure 9 , in combination with the above embodiments, in some embodiments, the size of the through hole 14 in the length direction X is L1, and the size of the compression cavity 11 in the length direction X is L2, which satisfies: 0.2≤L1 / L2≤0.3.

[0055] It can be understood that if the ratio of the size of the through hole 14 in the length direction X to the size of the compression cavity 11 in the length direction X is less than 0.2, it means that the size of the through hole 14 in the length direction X is too small. The small size of the through hole 14 will reduce the gas flow rate of the compression cavity 11 entering the containing cavity 12, thereby reducing the adjustment range of the gas amount. If the ratio of the size of the through hole 14 in the length direction X to the size of the compression cavity 11 in the length direction X is greater than 0.3, it means that the size of the through hole 14 in the length direction X is too large. The large size of the through hole 14 will make the size of the valve body part 22 larger, thereby affecting the sliding of the valve body part 22 in the containing cavity 12 and limiting the adjustment stroke of the valve body part 22.

[0056] Please refer to Figure 1 , in combination with the above embodiments, in some embodiments, the intake amount of the intake passage 31 is C, and the exhaust amount of the compressor 30 is M, which satisfies: 0.5≤M / C≤1.

[0057] It can be understood that when the stroke of the valve body 22 reaches the maximum, half of the gas entering through the intake passage 31 enters the inside of the containing cavity 12 through the through hole 14, so only half of the gas is discharged by the compressor 30, and at this time, M / C is 0.5. When the stroke of the valve body 22 is 0, that is, the valve body 22 completely covers the through hole 14, all the gas entering through the intake passage 31 is discharged by the compressor 30, and at this time, M / C is 1, so the gas regulation range of this structure is 50% to 100%.

[0058] According to the above structural scheme, the compressor 30 is used to pressurize the low-pressure water vapor in this embodiment, the flow regulation mode is slide valve regulation and circulation backflow regulation, the slide valve regulation is the structural regulation form in the above, and the slide valve regulation range is 50% to 100%, which accounts for the main part of the regulation. If a smaller steam flow needs to be processed, the circulation backflow regulation is used for assistance. According to the design calculation of the steam processing capacity, two through holes 14 are symmetrically arranged at the bottom of the cylinder block, the projection rectangular width of the through hole 14 is 150 mm, and the length is 230 mm. When the inlet steam flow is 20 t / h, the amount of steam that needs to be backflowed is 6 t, and through calculation, the valve body 22 needs to move and open 104 mm, which accounts for about 45% of the total length of the through hole 14, and the steam regulation amount is 76.9%. In the calculation process, the actual area of the through hole 14 is greater than the projection area, and the projection area is used for calculation, which is considered as a design margin. The working condition table of the compressor 30 is as follows:

[0059] The intake amount of the intake passage 31 of the compressor 30 is still 26 t / h, 6 t / h of steam is guided back to the intake passage 31 from the through hole 14 after the slide valve regulation, only 20 t / h of steam passes through the entire compression process, unnecessary work is avoided due to the compression of all the gas, and the energy-saving effect is remarkable.

[0060] The embodiment of the application also provides a gas quantity regulation method of a lead screw driven compressor, which is applied to the lead screw driven compressor in the above, and the method comprises the following steps: determining a target covering area of the valve body 22 to the through hole 14 according to a target gas quantity of the compressor 30; rotating one end of the lead screw part 23 located in the second cavity 122 to drive the valve body 22 to move in the length direction X in the first cavity 121; the relative position of the valve body 22 to the through hole 14 changes when the valve body 22 slides, and then the actual covering area of the valve body 22 to the through hole 14 is adjusted until the actual covering area is consistent with the target covering area; part of the gas in the compression cavity 11 enters the first cavity 121 through the region of the through hole 14 that is not covered, and then flows back to the intake passage 31 of the compressor 30 through the flow passage 13, so that the gas quantity of the compressor 30 is regulated.

[0061] In the description of the present application, the terms "first", "second", etc. are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0062] In the above embodiments, the description of each embodiment is focused on, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0063] The embodiments, implementation manners and related technical features of the present application can be combined or replaced with each other without conflict.

[0064] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification made to the above embodiment in accordance with the technical essence of the present application without departing from the technical solution content of the present application still falls within the scope of the technical solution of the present application.

Claims

1. A screw-driven compressor, characterized in that, include: The cylinder housing (10) has a compression chamber (11), a receiving chamber (12), a flow passage (13), and a through hole (14) connecting the compression chamber (11) and the receiving chamber (12). The receiving chamber (12) is connected to the flow passage (13), and the flow passage (13) is connected to the intake passage (31) of the compressor (30). The valve stem assembly (20) includes a baffle portion (21), a valve body portion (22), and a lead screw portion (23). The baffle portion (21) is disposed in the receiving cavity (12), dividing the receiving cavity (12) into a first cavity (121) and a second cavity (122). The first cavity (121) and the second cavity (122) are arranged at intervals along the length direction (X). The first cavity (121) communicates with the flow channel (13), and the first cavity (121) is connected to the pressure through the through hole (14). The constriction cavity (11) is connected, the valve body (22) is disposed in the first cavity (121), the lead screw (23) is disposed in the receiving cavity (12) and passes through the baffle (21) and the valve body (22) along the length direction (X), the lead screw (23) is connected to the valve body (22) in a driving connection, and the lead screw (23) is configured to drive the valve body (22) to move along the length direction (X) to adjust the coverage area of ​​the valve body (22) on the through hole (14).

2. The screw-driven compressor according to claim 1, characterized in that, The compression chamber (11) includes a first compression chamber (111) and a second compression chamber (112) that are connected to each other. There are two through holes (14). The two through holes (14) are arranged at intervals along the width direction (Y) and are respectively disposed on the inner wall of the first compression chamber (111) and the inner wall of the second compression chamber (112). The first compression chamber (111) is connected to the first cavity (121) through one of the through holes (14), and the second compression chamber (112) is connected to the first cavity (121) through the other through hole (14).

3. The screw-driven compressor according to claim 2, characterized in that, The receiving cavity (12) has a first inner wall surface (123) and a second inner wall surface (124) connected to each other, and one of the two through holes (14) is formed on the first inner wall surface (123) and the other is formed on the second inner wall surface (124); The valve body (22) includes a first contact surface (221) and a second contact surface (222). The first contact surface (221) is slidably connected to the first inner wall surface (123) and is used to cover at least a portion of the through hole (14) on the first inner wall surface (123). The second contact surface (222) is slidably connected to the second inner wall surface (124) and is used to cover at least a portion of the through hole (14) on the second inner wall surface (124).

4. The screw-driven compressor according to claim 2, characterized in that, There are two flow passages (13), which are arranged at intervals along the width direction (Y). Both flow passages (13) are connected to the air intake passage (31) of the compressor (30).

5. The screw-driven compressor according to claim 2, characterized in that, The first compression chamber (111) is provided with a female rotor (15), and the second compression chamber (112) is provided with a male rotor (16). The center distance between the female rotor (15) and the male rotor (16) is H1, and the dimension of the valve body (22) in the width direction (Y) is H2, satisfying: 0.5≤H2 / H1≤0.

7.

6. The screw-driven compressor according to claim 1, characterized in that, The cylinder housing (10) has a guide groove (17) communicating with the receiving cavity (12), the guide groove (17) extending along the length direction (X), and the valve body (22) includes a guide block (223) embedded in the guide groove (17).

7. The screw-driven compressor according to claim 1, characterized in that, The surface of the valve body (22) is provided with a coating structure (224), and the coefficient of friction of the coating structure (224) is μ, which satisfies: μ≤0.

2.

8. The screw-driven compressor according to claim 1, characterized in that, The baffle portion (21) includes: The main body (211) is disposed in the receiving cavity (12), dividing the receiving cavity (12) into the first cavity (121) and the second cavity (122), and the outer periphery of the main body (211) has a sealing groove (212). A sealing ring (213) is disposed in the sealing groove (212) to seal the connection between the main body (211) and the inner wall of the receiving cavity (12).

9. The screw-driven compressor according to claim 1, characterized in that, One end of the lead screw (23) is disposed in the second cavity (122). The bottom of the cylinder housing (10) has a connection hole (18) communicating with the second cavity (122). The connection hole (18) is used to allow the drive component to be embedded in the second cavity (122) and rotate one end of the lead screw (23).

10. The screw-driven compressor according to claim 9, characterized in that, One end of the lead screw (23) has a polygonal prism structure.

11. The screw-driven compressor according to claim 9, characterized in that, The surface of the lead screw (23) is provided with a thread, the thread profile is a trapezoidal thread, and the thread angle of the trapezoidal thread is α, satisfying: 30°≤α≤35°.

12. The screw-driven compressor according to claim 1, characterized in that, The cross-sectional area of ​​the flow channel (13) is A, and the cross-sectional area of ​​the through hole (14) is B, satisfying: 1.2≤A / B≤2.

13. The screw-driven compressor according to claim 1, characterized in that, The through hole (14) has a dimension of L1 in the length direction (X), and the compression cavity (11) has a dimension of L2 in the length direction (X), satisfying: 0.2≤L1 / L2≤0.

3.

14. The screw-driven compressor according to claim 1, characterized in that, The intake volume of the intake channel (31) is C, and the exhaust volume of the compressor (30) is M, satisfying: 0.5≤M / C≤1.

15. A method for regulating the gas volume of a screw-driven compressor, characterized in that, The method, applied to a screw-driven compressor as described in any one of claims 1 to 14, comprises: Based on the target air volume of the compressor (30), determine the target coverage area of ​​the valve body (22) over the through hole (14); One end of the lead screw (23) located in the second cavity (122) is rotated to drive the valve body (22) to move along the length direction (X) in the first cavity (121); When the valve body (22) slides, its relative position with the through hole (14) changes, thereby adjusting the actual coverage area of ​​the valve body (22) over the through hole (14) until the actual coverage area is consistent with the target coverage area. Some of the gas in the compression chamber (11) enters the first cavity (121) through the area not covered by the through hole (14), and then flows back to the air intake channel (31) of the compressor (30) through the flow channel (13), thereby realizing the regulation of the gas volume of the compressor (30).

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