Oil path system for adjusting capacity of screw compressor
By setting up an electromagnetic reversing valve and pipeline structure in the oil circuit system of the screw compressor, and using the oil pump to boost the oil pump to provide appropriate oil inlet pressure, the problem of insufficient oil inlet pressure in the screw compressor when capacity reduction is solved, ensuring the efficiency and stability of capacity adjustment.
Patent Information
- Application Number
- CN202422645725.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-10-30
AI Technical Summary
The screw compressor has insufficient oil pressure when the capacity is reduced, resulting in insufficient piston force to overcome air pressure and reduced capacity adjustment efficiency and stability.
An oil circuit system for capacity adjustment of screw compressors is designed. By setting up an electromagnetic reversing valve in front of the oil cylinder interface, and setting up the first and second pipelines in front of the valve respectively to connect to the oil cooler, the oil pump boost is used to achieve the appropriate oil inlet pressure under different working conditions, ensuring that the oil piston force is consistent or opposite to the direction of the gas pressure, and the movement of the capacity adjustment slide valve is controlled separately.
It realizes the provision of appropriate oil inlet pressure under different capacity adjustment conditions, ensures the efficiency and stability of capacity adjustment, and avoids the problem of unstable capacity adjustment caused by insufficient oil inlet pressure.
Smart Images
Figure CN223241617U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of screw compressors, in particular to an oil circuit system for capacity regulation of a screw compressor. Background Art
[0002] Screw compressor units are positive displacement refrigeration compressors that utilize a pair of intermeshing yin and yang rotors to rotate within the unit body, periodically changing the volume between each pair of rotor teeth to complete the suction, compression, and exhaust processes. They possess all the advantages of rotary compressors, such as small size, light weight, stable operation, few wearing parts, high efficiency, large single-stage pressure ratio, and stepless energy regulation. They have been rapidly developed and applied in the compressor industry.
[0003] During operation, a screw compressor's capacity is adjusted within a range of 15% to 100% via an internal capacity control slide valve. The capacity control slide valve forms an adjustable opening within the casing. With high-pressure exhaust air to the right and low-pressure intake air to the left, the slide valve is subjected to leftward pressure. The slide valve is connected to one end of the piston rod. The oil piston in the cylinder is connected to the other end of the piston rod. The hydraulic system controls the oil pump, solenoid valve, valves, and oil inlet and outlet ports to vary the force of the oil piston. This piston, driven by the piston rod, moves the slide valve back and forth, controlling the size of the opening and, in turn, the amount of compressed gas, thereby regulating the compressor's capacity.
[0004] When a screw compressor is de-loading, the oil inlet and outlet directions need to be switched compared to when it is being loaded. During de-loading, the piston force of the oil piston and the gas pressure are in opposite directions. If the oil inlet pressure is insufficient, the piston force will not be enough to overcome the gas pressure, slowing the movement of the capacity control slide valve toward the high-pressure side, resulting in reduced efficiency and stability in de-loading. Utility Model Content
[0005] The present invention provides an oil circuit system for capacity regulation of a screw compressor, which can provide appropriate oil inlet pressure according to different capacity regulation working conditions, thereby ensuring the efficiency and stability of capacity regulation. The technical solution is as follows:
[0006] The present invention provides an oil circuit system for capacity regulation of a screw compressor, comprising:
[0007] A compressor, an oil separator, an oil cooler, an oil pump, a first stop valve, a second stop valve and an electromagnetic reversing valve, wherein the oil-gas mixture outlet of the compressor is connected to the oil separator, the oil outlet of the oil separator is connected to the oil cooler, the oil outlet of the oil cooler is connected to the inlet of the first stop valve through a first pipeline, the oil pump is arranged on the first pipeline, the oil outlet of the oil cooler is connected to the inlet of the second stop valve through a second pipeline, and the outlets of the first stop valve and the second stop valve are connected to the oil cylinder interface of the compressor through the electromagnetic reversing valve.
[0008] Optionally, a pressure differential one-way valve is provided between the first pipeline and the second pipeline.
[0009] Optionally, an oil distribution seat is further included, and the oil distribution seat is arranged on the second pipeline. A plurality of oil supply pipes are arranged on the oil distribution seat.
[0010] Optionally, a temperature sensor is provided on the oil distribution seat.
[0011] Optionally, a pressure transmitter is further included, and the pressure transmitter is connected to the oil distribution seat.
[0012] Optionally, a third stop valve is provided between the pressure transmitter and the oil distribution seat.
[0013] Optionally, a pressure gauge is provided between the third stop valve and the oil distribution seat.
[0014] Optionally, a coarse oil filter is provided on the first pipeline and the second pipeline.
[0015] The beneficial effects of the technical solution provided by the embodiment of the utility model include at least:
[0016] The oil circuit system for capacity regulation of the screw compressor provided by the embodiment of the present utility model is adopted, by arranging an electromagnetic reversing valve in front of the oil cylinder interface of the compressor, and arranging a first pipeline and a second pipeline in front of the valve to connect with the oil outlet of the oil cooler. A first stop valve and a second stop valve are respectively arranged in front of the valve at the connection between the first pipeline and the second pipeline and the electromagnetic reversing valve, which can be opened and closed and adjusted according to the capacity increase and decrease load regulation working conditions of the compressor. An oil pump is arranged on the first pipeline, which can realize the oil pressure in the first pipeline to be greater than the exhaust pressure of the oil separator through its boosting, and distinguish it from the oil pressure in the second pipeline which is equal to the exhaust pressure, corresponding to the capacity reduction and increase load working conditions of the compressor respectively, and can provide appropriate oil inlet pressure according to different capacity regulation working conditions, thereby ensuring the efficiency and stability of capacity regulation. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0018] Figure 1 This is a structural diagram of an oil circuit system for capacity regulation of a screw compressor provided by an embodiment of the present utility model;
[0019] Figure 2 yes Figure 1 A partial structural cross-sectional view of a medium-screw compressor.
[0020] In the picture:
[0021] 1-compressor; 1-1-first pipeline; 2-oil separator; 2-1-second pipeline; 3-oil cooler; 4-oil pump; 5-first stop valve; 6-second stop valve; 7-solenoid reversing valve; 8-oil distribution seat; 9-oil coarse filter; 11-oil cylinder interface; 81-oil supply pipe; 82-temperature sensor; 83-pressure transmitter; 84-third stop valve; a-differential pressure check valve; b-first oil pipe; c-second oil pipe; m-capacity adjustment slide valve; n-casing; o-piston rod; p-oil piston. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0023] Figure 1 It is a structural schematic diagram of an oil circuit system for capacity regulation of a screw compressor provided by an embodiment of the present utility model. Figure 2 yes Figure 1 The partial structural cross-section of the screw compressor. Figures 1 to 2 As shown, an embodiment of the present invention provides an oil circuit system for capacity regulation of a screw compressor, comprising a compressor 1, an oil separator 2, an oil cooler 3, an oil pump 4, a first stop valve 5, a second stop valve 6 and an electromagnetic reversing valve 7. The oil-gas mixture outlet of the compressor 1 is connected to the oil separator 2, and the oil outlet of the oil separator 2 is connected to the oil cooler 3. The oil outlet of the oil cooler 3 is connected to the inlet of the first stop valve 5 through the first pipeline 1-1, the oil pump 4 is arranged on the first pipeline 1-1, the oil outlet of the oil cooler 3 is connected to the inlet of the second stop valve 6 through the second pipeline 2-1, and the outlets of the first stop valve 5 and the second stop valve 6 are connected to the cylinder interface 11 of the compressor 1 through the electromagnetic reversing valve 7.
[0024] In the embodiment of the present utility model, reference Figure 2In a screw compressor, the capacity control slide valve m forms an adjustable opening with the casing n. When compressed gas reaches the opening, it is bypassed, preventing compression. Under the control of the hydraulic system, the capacity control slide valve m can be moved back and forth, changing the size of the opening. A larger opening allows more gas to bypass, while a smaller opening allows less gas to bypass. By controlling the size of the opening, the amount of compressed gas can be controlled, thereby adjusting the capacity of the screw compressor. The right side of the capacity control slide valve m is exposed to high exhaust pressure, while the left side is exposed to low suction pressure. Therefore, it is subject to leftward pressure. The capacity control slide valve m is connected to one end of the piston rod o. The oil piston p in the cylinder is connected to the other end of the piston rod o. The hydraulic system controls the oil pump 4, various supporting valves, and the cylinder interface 11 to change the magnitude and direction of the oil piston force. This causes the oil piston p to drive the capacity control slide valve m back and forth via the piston rod o.
[0025] Before the screw compressor starts, oil pump 4 starts to establish pre-lubrication and provide pressure to the oil system. Once the screw compressor is operating stably, oil pump 4 stops. Compressor 1 discharges high-pressure oil and gas into oil separator 2. The pressure in oil separator 2 is also the exhaust pressure. The oil system uses the high-pressure oil in oil separator 2 as the pressure source, replacing oil pump 4.
[0026] When compressor 1 increases capacity, solenoid reversing valve 7 is adjusted to the increase position. First stop valve 5 is closed, and second stop valve 6 is open. Oil in second pipeline 2-1 flows through solenoid reversing valve 7 and enters first oil pipe b, where the oil pressure is equal to the exhaust pressure of oil separator 2 and is at the high-pressure end. Oil returns through second oil pipe c, where it is at the low-pressure end. At this point, the piston force acting on oil piston p is directed leftward, and so is the gas pressure. This piston force and the gas pressure act in the same direction, causing capacity adjustment slide valve m to move leftward, achieving capacity increase.
[0027] When compressor 1 is unloading capacity, solenoid reversing valve 7 is adjusted to the unloading position. At this point, first shut-off valve 5 is open, and second shut-off valve 6 is closed. The oil in first pipeline 1-1, pressurized by oil pump 4, flows through solenoid reversing valve 7 and enters second oil pipe c, reaching the high-pressure end. Oil exits first oil pipe b, reaching the low-pressure end. At this point, the piston force acting on oil piston p is directed rightward, while the gas pressure is directed leftward. The piston force and gas pressure act in opposite directions. The oil pressure, boosted by oil pump 4, increases from the exhaust pressure to 0.4-0.6 MPa above the exhaust pressure. This increases the oil inlet pressure in second oil pipe c to exceed the gas pressure on the right side, pushing capacity control slide valve m rightward, achieving unloading capacity. Furthermore, the first pipeline 1-1 and the second pipeline 2-1 are isolated by setting a pressure difference check valve a, so that the oil pressures of the two different pipelines are kept different on the oil pipeline that is connected as a whole, ensuring that the oil in the first pipeline 1-1 is 0.4 to 0.6 MPa higher than the exhaust pressure, and the oil in the second pipeline 2-1 is equal to the exhaust pressure.
[0028] The oil circuit system for capacity regulation of the screw compressor provided by the embodiment of the present utility model is provided by setting an electromagnetic reversing valve 7 in front of the oil cylinder interface 11 of the compressor 1, and respectively setting a first pipeline 1-1 and a second pipeline 2-1 in front of the valve to connect with the oil outlet of the oil cooler 3. A first stop valve 5 and a second stop valve 6 are respectively provided in front of the valve at the connection between the first pipeline 1-1 and the second pipeline 2-1 and the electromagnetic reversing valve 7, which can be opened and closed and adjusted according to the capacity increase and decrease load regulation working conditions of the compressor 1. An oil pump 4 is provided on the first pipeline 1-1, which can achieve the oil pressure in the first pipeline 1-1 to be greater than the exhaust pressure of the oil separator 2 through its boosting, and distinguish it from the oil pressure in the second pipeline 2-1 which is equal to the exhaust pressure, corresponding to the capacity reduction and increase load working conditions of the compressor 1, respectively, and can provide appropriate oil inlet pressure according to different capacity regulation working conditions, thereby ensuring the efficiency and stability of capacity regulation.
[0029] Optionally, an oil distribution block 8 is provided on the second pipeline 2-1 and is equipped with multiple oil supply pipes 81. For example, in this embodiment of the present invention, during load shedding, the second shut-off valve 6 is closed, but the oil in the second pipeline 2-1 can be distributed and supplied through the oil distribution block 8 to other oil-consuming areas besides the capacity regulating oil pipe. The oil distribution block 8 is equipped with a temperature sensor 82 and a pressure transmitter 83, enabling real-time monitoring of the oil temperature and pressure of the oil passing through the oil distribution block 8. A third shut-off valve 84 is provided between the pressure transmitter 83 and the oil distribution block 8, facilitating the immediate shut-off and disassembly and maintenance of the pressure transmitter 83. Furthermore, a pressure gauge 85 is provided between the third shut-off valve 84 and the oil distribution block 8, allowing personnel to manually monitor the oil pressure passing through the oil distribution block 8.
[0030] Optionally, the first pipeline 1-1 and the second pipeline 2-1 are provided with a coarse oil filter 9. For example, in the embodiment of the present invention, the oil outlet of the oil cooler 3 can be filtered to avoid pipeline blockage and improve the smoothness of the oil system circulation.
[0031] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by persons of ordinary skill in the field to which the present invention belongs. The terms "first", "second" and similar words used in the specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "include" or "comprising" mean that the elements or objects appearing before "include" or "comprising" include the elements or objects listed after "include" or "comprising" and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "upper", "lower", "left", and "right" are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0032] The above description is only an optional embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. An oil circuit system for capacity adjustment of a screw compressor, characterized in that: include: A compressor (1), an oil separator (2), an oil cooler (3), an oil pump (4), a first stop valve (5), a second stop valve (6) and an electromagnetic reversing valve (7); the oil-gas mixture outlet of the compressor (1) is connected to the oil separator (2); the oil outlet of the oil separator (2) is connected to the oil cooler (3); the oil outlet of the oil cooler (3) is connected to the inlet of the first stop valve (5) through a first pipeline (1-1); the oil pump (4) is arranged on the first pipeline (1-1); the oil outlet of the oil cooler (3) is connected to the inlet of the second stop valve (6) through a second pipeline (2-1); the outlets of the first stop valve (5) and the second stop valve (6) are connected to the oil cylinder interface (11) of the compressor (1) through the electromagnetic reversing valve (7).
2. The oil circuit system for capacity adjustment of a screw compressor according to claim 1, characterized in that: A pressure differential one-way valve (a) is provided between the first pipeline (1-1) and the second pipeline (2-1).
3. The oil circuit system for capacity adjustment of a screw compressor according to claim 2, characterized in that: It also includes an oil distribution seat (8), which is arranged on the second pipeline (2-1), and a plurality of oil supply pipes (81) are arranged on the oil distribution seat (8).
4. The oil circuit system for capacity adjustment of a screw compressor according to claim 3, characterized in that: A temperature sensor (82) is provided on the oil distribution seat (8).
5. The oil circuit system for capacity adjustment of a screw compressor according to claim 3, characterized in that: It also includes a pressure transmitter (83), which is connected to the oil distribution seat (8).
6. The oil circuit system for capacity adjustment of a screw compressor according to claim 5, characterized in that: A third stop valve (84) is provided between the pressure transmitter (83) and the oil distribution seat (8).
7. The oil circuit system for capacity adjustment of a screw compressor according to claim 6, characterized in that: A pressure gauge (85) is provided between the third stop valve (84) and the oil distribution seat (8).
8. The oil circuit system for capacity adjustment of a screw compressor according to claim 1, characterized in that: The first pipeline (1-1) and the second pipeline (2-1) are provided with oil coarse filters (9).