CN113550902A - Unloading control method of screw compressor - Google Patents
Unloading control method of screw compressor Download PDFInfo
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- CN113550902A CN113550902A CN202010334494.2A CN202010334494A CN113550902A CN 113550902 A CN113550902 A CN 113550902A CN 202010334494 A CN202010334494 A CN 202010334494A CN 113550902 A CN113550902 A CN 113550902A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/28—Safety arrangements; Monitoring
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/18—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by varying the volume of the working chamber
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- General Engineering & Computer Science (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
Abstract
The invention belongs to the technical field of compressors and aims to solve the problem that the normal operation of the conventional screw compressor is affected by the problems of shutdown, alarm and the like. To this end, the present invention provides an unloading control method of a screw compressor, the unloading control method comprising: when the screw compressor starts to unload from a full-load state, the second oil drain valve and the third oil drain valve are controlled to drain oil from the second oil drain pipe and the third oil drain pipe simultaneously and maintain the set time, so that the piston moves from a full-load position to a position of the second oil drain port; when the piston moves to the position of the second oil drainage port, the second oil drainage valve is controlled to enable the second oil drainage pipe to stop oil drainage, and the third oil drainage valve is controlled to keep oil drainage of the third oil drainage pipe, so that the piston is kept at the position of the second oil drainage port. The invention can improve the unloading speed of the screw compressor, shorten the unloading time and avoid the problems of shutdown or alarm of the screw compressor caused by overlong unloading time.
Description
Technical Field
The invention belongs to the technical field of compressors, and particularly provides an unloading control method of a screw compressor.
Background
A compressor is a fluid mechanical device capable of lifting a low-pressure gas into a high-pressure gas, and is classified into a reciprocating compressor, a screw compressor, a rotary compressor, a scroll compressor, a centrifugal compressor, and the like according to its category, and the screw compressor is generally used in large commercial and industrial systems.
Taking a screw compressor of a commercial air conditioner as an example, the commercial air conditioner is a device capable of adjusting the indoor environment temperature, the working cycle of the screw compressor can be divided into three processes of air suction, compression and exhaust, and the screw compressor can provide power for the refrigeration cycle of the commercial air conditioner.
Therefore, there is a need in the art for an unloading control method of a screw compressor to solve the above problems.
Disclosure of Invention
In order to solve the problems in the prior art, namely to solve the problem that the normal operation of the conventional screw compressor is affected by the problems of halt, alarm and the like frequently, the invention provides an unloading control method of the screw compressor, the screw compressor comprises a piston cavity, a piston rod, a capacity regulating slide block, an oil supply pipe, a first oil drain pipe, a second oil drain pipe, a third oil drain pipe and an oil groove, a first oil drain valve is arranged on the first oil drain pipe, a second oil drain valve is arranged on the second oil drain pipe, a third oil drain valve is arranged on the third oil drain pipe, two ends of the piston rod are respectively connected with the piston and the capacity regulating slide block, the piston is arranged to move relative to the piston cavity according to the change of the oil quantity in the piston cavity so as to enable the capacity regulating slide block to move, the capacity regulating slide block can be matched with a rotor of the screw compressor so as to regulate the load of the screw compressor, and an inlet of the oil supply pipe is communicated with the oil groove, the export and the piston chamber intercommunication of fuel feeding pipe, the entry and the fuel feeding pipe intercommunication of first draining pipe, the entry and the first draining mouth intercommunication in piston chamber of second draining pipe, the entry and the second draining mouth intercommunication in piston chamber of third draining pipe, the export of first draining pipe, the export of second draining pipe and the export of third draining pipe all communicate with the oil groove, first draining mouth and second draining mouth set gradually for the shift-out direction in piston chamber along the piston, this uninstallation control method includes: when the screw compressor starts to unload from a full-load state, the second oil drain valve and the third oil drain valve are controlled to drain oil from the second oil drain pipe and the third oil drain pipe simultaneously and maintain the set time, so that the piston moves from a full-load position to a position of the second oil drain port; when the piston moves to the position of the second oil drainage port, the second oil drainage valve is controlled to enable the second oil drainage pipe to stop oil drainage, and the third oil drainage valve is controlled to keep oil drainage of the third oil drainage pipe, so that the piston is kept at the position of the second oil drainage port.
In a preferred technical solution of the unloading control method, the oil supply pipe is provided with an oil supply valve, and the unloading control method further includes, while controlling the second and third spill valves to drain oil from the second and third spill pipes simultaneously and maintain a set time: the oil supply valve is controlled to stop the supply of oil to the oil supply pipe and maintain the set time.
In a preferred embodiment of the unloading control method, after the step of controlling the second spill valve to stop the second spill pipe from spilling oil and controlling the third spill valve to maintain the third spill pipe from spilling oil, the unloading control method further includes: acquiring an input control instruction; and if the input control command is an unloading command, continuing unloading the screw compressor.
In a preferred embodiment of the unloading control method, a part of the oil supply pipe is a capillary.
In a preferred embodiment of the above-described unloading control method, the oil supply valve is provided on an upstream side of the capillary tube in a flow direction of the oil in the oil supply pipe.
In a preferred embodiment of the above-described unloading control method, the oil supply valve is provided on a downstream side of the capillary tube in a flow direction of the oil in the oil supply pipe.
In a preferred embodiment of the unloading control method, a filter is disposed at a suction port of the screw compressor.
In a preferred embodiment of the unloading control method, the oil groove is formed in an inner bottom of a casing of the screw compressor.
In a preferred embodiment of the unloading control method, the suction port of the screw compressor is provided at an end of the casing.
In a preferred embodiment of the unloading control method, the discharge port of the screw compressor is provided at the top of the casing.
In the preferred technical scheme of the invention, when the screw compressor starts to unload from a full-load state, the second oil drain valve and the third oil drain valve are controlled to drain oil from the second oil drain pipe and the third oil drain pipe simultaneously and maintain a set time, so that the piston moves from a full-load position to a position of the second oil drain port; when the piston moves to the position of the second oil drainage port, the second oil drainage valve is controlled to stop oil drainage of the second oil drainage pipe and the third oil drainage valve is controlled to keep oil drainage of the third oil drainage pipe, so that the piston is kept at the position of the second oil drainage port, and by the arrangement, the screw compressor can simultaneously drain oil through the second oil drainage pipe and the third oil drainage pipe when starting to unload from a full-load state, compared with the prior art that oil drainage can be carried out only through one oil drainage pipe, the unloading speed is greatly increased, the time for unloading to the corresponding load state is shortened, the problem that the unloading time is too long due to too low unloading speed of the screw compressor under the working conditions of low temperature or high pressure and the like, so that the air conditioning unit is shut down or gives an alarm and the like is solved, other structures are not required to be additionally arranged, and the production cost cannot be increased; in addition, when the piston moves to the position of second draining port, through controlling the second bleeder valve so that the second draining pipe stops draining and control the third bleeder valve and keep the draining of third draining pipe, make the piston can keep the position at the second draining port, so that screw compressor can keep current load state, avoid screw compressor just to change current load state when not receiving control command, promote user's use and experience.
Further, through being provided with the fuel feed valve on the fuel feed pipe, when "control second bleeder valve and third bleeder valve so that second bleeder valve and third bleeder valve drain simultaneously and maintain the step of settlement time", control the fuel feed valve so that the fuel feed pipe stops the fuel feeding and maintain the settlement time, through such setting, make screw compressor through second bleeder valve and third bleeder pipe drain simultaneously, still make the fuel feed pipe stop the fuel feeding, compare with prior art, not only increased the pipeline of piston chamber draining, still stopped the oil feed of piston chamber, further improve the uninstallation speed, shorten the time of uninstalling to the corresponding load state, avoid screw compressor unloading speed too slow under operating modes such as low temperature or high pressure and lead to the uninstallation time and thus make air conditioning unit appear the problem such as shut down or report to the police, further promote user's use and experience.
Drawings
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings in conjunction with a screw compressor of a commercial air conditioner, in which:
fig. 1 is a flowchart of an unloading control method of a screw compressor of a commercial air conditioner of the present invention;
fig. 2 is a partial structural view of a screw compressor of a commercial air conditioner according to the present invention.
Reference numerals: 1. a piston cavity; 2. a piston; 3. a piston rod; 4. a volume adjusting slide block; 5. an oil supply pipe; 6. a first oil drainage pipe; 7. a second oil drainage pipe; 8. a third oil drainage pipe; 9. an oil sump; 10. a first oil drain valve; 11. a second oil drain valve; 12. a third oil drain valve; 13. a rotor; 14. an oil supply valve; 15. a capillary tube; 16. an air suction port; 17. a filter; 18. a housing; 19. and (7) an exhaust port.
Detailed Description
First, it should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present invention, and are not intended to limit the scope of the present invention. For example, although the present invention has been described in connection with a screw compressor of a commercial air conditioner, the unloading control method of the screw compressor of the present invention is also applicable to a screw compressor in food production, pharmaceutical production, textile and other equipment, and such adjustment and change of the application objects should not be construed as limiting the present invention, and should be limited within the scope of the present invention.
It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
Furthermore, it should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The invention provides an unloading control method of a screw compressor, aiming at solving the problem that the normal operation of the screw compressor of the existing commercial air conditioner is affected by the problems of shutdown, alarm and the like frequently caused by the screw compressor in the prior art, and the problem that the unloading time is too long due to too low unloading speed of the screw compressor under the working conditions of low temperature, high pressure and the like, so that an air conditioner unit is shut down or alarms and the like is solved.
Specifically, as shown in fig. 2, the screw compressor of the present invention includes a housing, a piston cavity 1, a piston 2, a piston rod 3, a capacity-adjusting slider 4, an oil supply pipe 5, a first oil drain pipe 6, a second oil drain pipe 7, a third oil drain pipe 8 and an oil groove 9, wherein the piston cavity 1, the piston 2, the piston rod 3, the capacity-adjusting slider 4, the oil supply pipe 5, the first oil drain pipe 6, the second oil drain pipe 7, the third oil drain pipe 8 and the oil groove 9 are all disposed in the housing, the housing is provided with an air suction port (as a refrigerant inlet) and an air discharge port (as a refrigerant outlet), the first oil drain pipe 6 is provided with a first oil drain valve 10, the second oil drain pipe 7 is provided with a second oil drain valve 11, the third oil drain pipe 8 is provided with a third oil drain valve 12, both ends of the piston rod 3 are respectively connected to the piston 2 and the capacity-adjusting slider 4, the piston 2 is configured to be able to move relative to the piston cavity 1 according to the change of the oil amount in the piston cavity 1 to move the capacity-adjusting slider 4, the volume adjusting slide block 4 can be matched with a rotor 13 of the screw compressor to adjust the load of the screw compressor, an inlet of the oil supply pipe 5 is communicated with the oil groove 9, an outlet of the oil supply pipe 5 is communicated with the piston cavity 1, an inlet of the first oil drainage pipe 6 is communicated with the oil supply pipe 5, an inlet of the second oil drainage pipe 7 is communicated with a first oil drainage port of the piston cavity 1, an inlet of the third oil drainage pipe 8 is communicated with a second oil drainage port of the piston cavity 1, an outlet of the first oil drainage pipe 6, an outlet of the second oil drainage pipe 7 and an outlet of the third oil drainage pipe 8 are communicated with the oil groove 9, and the first oil drainage port and the second oil drainage port are sequentially arranged along the moving-out direction of the piston 2 relative to the piston cavity 1. The working principle of the screw compressor is that oil in the oil groove 9 flows into the piston cavity 1 through the oil supply pipe 5, the oil in the piston cavity 1 flows into the oil groove 9 through the oil drain pipe, the oil pressure is adjusted by adjusting the oil quantity in the piston cavity 1, the piston 2 in the piston cavity 1 is pushed to move under the action of the oil pressure, the piston 2 moves to drive the volume adjusting slide block 4 to move through the piston rod 3, the volume ratio is adjusted by adjusting the position of the volume adjusting slide block 4 and matching with the rotor 13, for example, the volume adjusting slide block 4 can be adjusted to 25% load, 50% load, 75% load or 100% load (correspondingly, the first oil drain valve is a 25% oil drain valve, the second oil drain valve is a 50% oil drain valve, and the third oil drain valve is a 75% oil drain valve), the load increasing process of the screw compressor is called a loading process, for example, the load is loaded to 100% load by 75% load, at the moment, the oil in the oil groove 9 flows into the piston cavity 1 through the oil supply pipe 5, the oil quantity in the piston cavity 1 is increased, the oil pressure is increased, the piston 2 moves out relative to the piston cavity 1 to drive the capacity adjusting slide block 4 to move from the position corresponding to 75% of load to the position corresponding to 100% of load, the process of load reduction is called unloading process, for example, the process of load reduction is from 100% of load to 75% of load, at this time, the oil quantity flowing into the piston cavity 1 through the oil supply pipe 5 is smaller than the oil quantity flowing out of the piston cavity 1 through the oil drainage pipe, the oil quantity in the piston cavity 1 is reduced, the oil pressure is reduced, the piston 2 moves in relative to the piston cavity 1 to drive the capacity adjusting slide block 4 to move from the position corresponding to 100% of load to the position corresponding to 75% of load (namely, the position of a second oil drainage port is located). In the prior art, when the screw compressor is unloaded from 100% load to 75% load, the third oil drain valve 12 is controlled to enable the third oil drain pipe 8 to start draining oil until the piston 2 moves to the position of the second oil drain opening, at the moment, the capacity adjusting slide block 4 is located at the position corresponding to 75% load, when the screw compressor is unloaded from 75% load to 50% load, the second oil drain valve 11 is controlled to enable the second oil drain pipe 7 to start draining oil until the piston 2 moves to the position of the first oil drain opening, at the moment, the capacity adjusting slide block 4 is located at the position corresponding to 50% load, when the screw compressor is unloaded from 50% load to 25% load, the first oil drain valve 10 is controlled to enable the first oil drain pipe 6 to start draining oil until the piston 2 moves to enable the capacity adjusting slide block 4 to be located at the position corresponding to 25% load, and in the process, the oil supply pipe 5 is supplied all the time.
Aiming at the problems that the existing commercial air conditioners pointed out in the background art sometimes have the conditions of shutdown, alarm and the like, and the conditions do not find specific causes all the time, the inventor tests, analyzes and compares the problems repeatedly for a long time, and the problems are mainly caused by the fact that the unloading time is too long due to the fact that the unloading speed of the screw compressor is too slow under the working conditions of low temperature, high pressure and the like.
In view of the above, the present invention particularly provides an unloading control method for a screw compressor, as shown in fig. 1 and 2, the unloading control method comprising: when the screw compressor starts to unload from a full-load state, the second oil drain valve 11 and the third oil drain valve 12 are controlled to drain oil from the second oil drain pipe 7 and the third oil drain pipe 8 simultaneously and maintain the set time, so that the piston 2 moves from a full-load position to a position of a second oil drain port; when the piston 2 moves to the position of the second oil drainage port, the second oil drainage valve 11 is controlled to enable the second oil drainage pipe 7 to stop oil drainage and the third oil drainage valve 12 to keep oil drainage of the third oil drainage pipe 8, so that the piston 2 is kept at the position of the second oil drainage port, namely oil drainage through two oil drainage pipes is changed from oil drainage through only one oil drainage pipe in the prior art, the oil drainage speed is improved, the screw compressor is enabled to be quickly unloaded to a corresponding load, the unloading time is shortened, and the problem that the screw compressor is shut down or gives an alarm due to the fact that the unloading speed is too slow, the unloading time is overlong, and therefore the air conditioning unit is enabled to be overlong is avoided. The set time here is the time required for the piston 2 to move from the full-load position to the position of the second drain port, and for this set time, a person skilled in the art can test and obtain through repeated experiments, after the second drain pipe 7 and the third drain pipe 8 drain oil simultaneously and maintain the set time, the piston 2 has moved to the position of the second drain port, that is, has unloaded from the full-load position to the load position corresponding to the second drain port, at this time, the second drain pipe 7 stops draining oil and keeps the third drain pipe 8 draining oil, so that the piston 2 is kept at the position of the second drain port under the action of pressure, and it should be noted that the moving-in movement of the piston 2 relative to the piston cavity 1 can be realized through a spring. In a possible case, similar to the above, the load position corresponding to the second oil drainage port is 75% load position, and the load position corresponding to the first oil drainage port is 50% load position, of course, the load positions corresponding to the first oil drainage port and the second oil drainage port are not limited thereto, and those skilled in the art can flexibly set the load positions, for example, the load position corresponding to the second oil drainage port is 50% load position, and the load position corresponding to the first oil drainage port is 75% load position, and the specific adjustment and change of the load positions corresponding to the first oil drainage port and the second oil drainage port should be limited within the protection scope of the present invention without departing from the principle and scope of the present invention.
The state of the first spill valve 10 may be set arbitrarily, for example, the first spill valve 10 may be set to be closed to stop the first spill pipe 6 from spilling oil in the energized state, and to be opened to start the first spill pipe 6 from spilling oil in the de-energized state, and of course, the first spill valve 10 may be set to be opened to start the first spill pipe 6 from spilling oil in the energized state, and to be closed to stop the first spill pipe 6 from spilling oil in the de-energized state; similarly, the state of the second spill valve 11 may be set arbitrarily, for example, the second spill valve 11 may be set to be closed to stop the second spill pipe 7 from spilling oil in the energized state, and to be opened to start the second spill pipe 7 from spilling oil in the de-energized state, and of course, the second spill valve 11 may be set to be opened to start the second spill pipe 7 from spilling oil in the energized state, and to be closed to stop the second spill pipe 7 from spilling oil in the de-energized state; similarly, the third spill valve 12 may be set in any state, for example, the third spill valve 12 may be set so as to close in the energized state to stop the third spill pipe 8 from spilling oil, and to open in the de-energized state to start the third spill pipe 8 from spilling oil, but of course, the third spill valve 12 may be set so as to open in the energized state to start the third spill pipe 8 from spilling oil, and to close in the de-energized state to stop the third spill pipe 8 from spilling oil.
Preferably, as shown in fig. 1 and 2, the oil supply pipe 5 is provided with an oil supply valve 14, and the unloading control method of the present invention further includes, while the step of controlling the second and third spill valves 11 and 12 to simultaneously spill the oil in the second and third spill pipes 7 and 8 for a set time, the step of: the oil supply valve 14 is controlled to stop oil supply of the oil supply pipe 5 and maintain the set time, so that not only is an oil drainage pipeline of the piston cavity 1 increased, but also oil inlet of the piston cavity 1 is stopped, the unloading speed is further improved, and the time for unloading to a corresponding load state is shortened. After the oil supply pipe 5 stops supplying oil and is maintained for a set time, the piston 2 moves to the position of the second oil drainage port, namely, the piston 2 is unloaded from 100% load to 75% load, the oil supply valve 14 is controlled to enable the oil supply pipe 5 to recover supplying oil, so that the piston 2 is kept at the position of the second oil drainage port under the action of pressure, and the capacity adjusting slide block 4 is kept at the position corresponding to 75% load. The state of the oil supply valve 14 may be set arbitrarily, and for example, the oil supply valve 14 may be set to close to stop the supply of oil to the oil supply pipe 5 in the energized state and to open to start the supply of oil to the oil supply pipe 5 in the de-energized state, but the oil supply valve 14 may be set to open to start the supply of oil to the oil supply pipe 5 in the energized state and to close to stop the supply of oil to the oil supply pipe 5 in the de-energized state.
Preferably, after the step of controlling the second spill valve 11 to stop the second spill pipe 7 from spilling oil and controlling the third spill valve 12 to keep the third spill pipe 8 from spilling oil, the unloading control method of the invention further includes: acquiring an input control instruction; if the input control instruction is an unloading instruction, the screw compressor is continuously unloaded; if the input control instruction is a loading instruction, loading the screw compressor; and if the control instruction is not acquired, keeping the screw compressor in the existing load state.
Preferably, as shown in fig. 2, a part of the oil supply pipe 5 is provided as a capillary 15 to slow down the oil supply speed of the oil supply pipe 5, so as to avoid that the too fast oil supply speed of the oil supply pipe 5 affects the loading and unloading of the screw compressor. The capillary tube 15 may be provided on the outlet side of the oil supply pipe 5, or may be provided at another position of the oil supply pipe 5.
In one possible case, as shown in fig. 2, the oil supply valve 14 is provided on the upstream side of the capillary tube 15 in the flow direction of the oil in the oil supply pipe 5.
In another possible case, the oil supply valve 14 is provided on the downstream side of the capillary tube 15 in the flow direction of the oil in the oil supply pipe 5.
Preferably, as shown in fig. 2, a filter 17 is disposed at the suction port 16 of the screw compressor to filter the gas entering the interior of the screw compressor, but of course, the filter 17 may not be disposed at the suction port 16 of the screw compressor, and the gas may directly enter the interior of the screw compressor.
Preferably, as shown in fig. 2, the oil groove 9 is formed at the inner bottom of the casing 18 of the screw compressor, the inlet of the oil supply pipe 5 is communicated with the oil groove 9, the outlet of the oil drain pipe is communicated with the oil groove 9, the oil in the oil groove 9 enters the piston cavity 1 through the oil supply pipe 5, the oil in the piston cavity 1 enters the oil groove 9 through the oil drain pipe to form an oil circuit circulation, and the oil groove 9 may be formed at other positions of the screw compressor.
The skilled person can flexibly set the position of the suction port 16 of the screw compressor, and in a possible case, as shown in fig. 2, the suction port 16 of the screw compressor is disposed at the end of the casing 18, of course, the suction port 16 of the screw compressor can also be disposed at the top of the casing 18, or disposed at other positions, and such specific adjustment and change of the position of the suction port 16 of the screw compressor without departing from the principle and scope of the present invention shall be limited within the protection scope of the present invention.
The position of the discharge port 19 of the screw compressor can be flexibly set by those skilled in the art, and in a possible case, as shown in fig. 2, the discharge port 19 of the screw compressor is arranged on the top of the housing 18, of course, the discharge port 19 of the screw compressor can also be arranged on the end of the housing 18, or arranged in other positions, and such specific adjustment and change of the arrangement position of the discharge port 19 of the screw compressor can be realized without departing from the principle and scope of the present invention, and should be limited within the protection scope of the present invention.
So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.
Claims (10)
1. An unloading control method of a screw compressor is characterized in that the screw compressor comprises a piston cavity, a piston rod, a capacity adjusting slide block, an oil supply pipe, a first oil drain pipe, a second oil drain pipe, a third oil drain pipe and an oil groove, wherein a first oil drain valve is arranged on the first oil drain pipe, a second oil drain valve is arranged on the second oil drain pipe, a third oil drain valve is arranged on the third oil drain pipe, two ends of the piston rod are respectively connected with the piston and the capacity adjusting slide block, the piston is arranged to move relative to the piston cavity according to the change of oil quantity in the piston cavity so as to enable the capacity adjusting slide block to move, the capacity adjusting slide block can be matched with a rotor of the screw compressor to adjust the load of the screw compressor,
the inlet of the oil supply pipe is communicated with the oil groove, the outlet of the oil supply pipe is communicated with the piston cavity, the inlet of the first oil drainage pipe is communicated with the oil supply pipe, the inlet of the second oil drainage pipe is communicated with the first oil drainage port of the piston cavity, the inlet of the third oil drainage pipe is communicated with the second oil drainage port of the piston cavity, the outlet of the first oil drainage pipe, the outlet of the second oil drainage pipe and the outlet of the third oil drainage pipe are all communicated with the oil groove, the first oil drainage port and the second oil drainage port are sequentially arranged along the moving-out direction of the piston relative to the piston cavity,
the unloading control method comprises the following steps:
when the screw compressor starts to unload from a full-load state, the second oil drain valve and the third oil drain valve are controlled to drain oil from the second oil drain pipe and the third oil drain pipe simultaneously and maintain a set time, so that the piston moves from a full-load position to a position of the second oil drain port;
when the piston moves to the position of the second oil drainage port, the second oil drainage valve is controlled to stop oil drainage of the second oil drainage pipe, and the third oil drainage valve is controlled to keep oil drainage of the third oil drainage pipe, so that the piston is kept at the position of the second oil drainage port.
2. The unloading control method according to claim 1, wherein an oil supply valve is provided on the oil supply pipe,
while the step of controlling the second and third spill valves to simultaneously spill the oil in the second and third spill pipes for the set time, the unloading control method further includes:
and controlling the oil supply valve to stop the oil supply of the oil supply pipe and maintain the set time.
3. The unloading control method of claim 1, further comprising, after the step of controlling the second spill valve to stop draining the second spill pipe and controlling the third spill valve to maintain draining the third spill pipe:
acquiring an input control instruction;
and if the input control command is an unloading command, continuing unloading the screw compressor.
4. The unloading control method according to claim 1, wherein a part of the oil supply pipe is provided as a capillary tube.
5. The unloading control method according to claim 4, wherein the oil supply valve is provided on an upstream side of the capillary tube in a flow direction of the oil in the oil supply pipe.
6. The unloading control method according to claim 4, wherein the oil supply valve is provided on a downstream side of the capillary tube in a flow direction of the oil in the oil supply pipe.
7. Unloading control method according to claim 1, characterized in that a filter is provided at the suction of the screw compressor.
8. The unloading control method according to claim 1, wherein the oil groove is formed at an inner bottom of a casing of the screw compressor.
9. The unloading control method of claim 8, wherein a suction port of the screw compressor is provided at an end of the casing.
10. The unloading control method of claim 8, wherein a discharge port of the screw compressor is provided at a top of the housing.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010334494.2A CN113550902B (en) | 2020-04-24 | 2020-04-24 | Unloading control method of screw compressor |
| PCT/CN2021/080348 WO2021213064A1 (en) | 2020-04-24 | 2021-03-12 | Unloading control method for screw compressor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010334494.2A CN113550902B (en) | 2020-04-24 | 2020-04-24 | Unloading control method of screw compressor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113550902A true CN113550902A (en) | 2021-10-26 |
| CN113550902B CN113550902B (en) | 2023-03-31 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010334494.2A Active CN113550902B (en) | 2020-04-24 | 2020-04-24 | Unloading control method of screw compressor |
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| Country | Link |
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| CN (1) | CN113550902B (en) |
| WO (1) | WO2021213064A1 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06173872A (en) * | 1992-12-03 | 1994-06-21 | Hitachi Ltd | Screw compressor |
| JPH07259778A (en) * | 1994-03-18 | 1995-10-09 | Daikin Ind Ltd | Capacity control device for screw compressor |
| US6276911B1 (en) * | 1999-07-26 | 2001-08-21 | Bitzer Kuehlmaschinenbau Gmbh | Screw compressor |
| CN101014771A (en) * | 2004-03-03 | 2007-08-08 | 雷弗孔普股份有限公司 | Volumetric screw compressor provided with delivery adjustment device |
| CN104500399A (en) * | 2014-09-15 | 2015-04-08 | 汉钟精机股份有限公司 | Compressor slide valve position control structure |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6649746B2 (en) * | 2015-11-10 | 2020-02-19 | 北越工業株式会社 | Oil-cooled screw compressor control method and oil-cooled screw compressor |
| CN107620709A (en) * | 2017-07-28 | 2018-01-23 | 无锡锡压压缩机有限公司 | A kind of fuel injection helical lobe compressor adds uninstalling system |
| CN110966195B (en) * | 2019-12-05 | 2024-04-19 | 珠海格力电器股份有限公司 | System and method for accurately controlling automatic loading stability of screw compressor and air conditioner |
| CN111794969A (en) * | 2020-04-24 | 2020-10-20 | 青岛海尔空调电子有限公司 | Unloading control method of screw compressor |
-
2020
- 2020-04-24 CN CN202010334494.2A patent/CN113550902B/en active Active
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2021
- 2021-03-12 WO PCT/CN2021/080348 patent/WO2021213064A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06173872A (en) * | 1992-12-03 | 1994-06-21 | Hitachi Ltd | Screw compressor |
| JPH07259778A (en) * | 1994-03-18 | 1995-10-09 | Daikin Ind Ltd | Capacity control device for screw compressor |
| US6276911B1 (en) * | 1999-07-26 | 2001-08-21 | Bitzer Kuehlmaschinenbau Gmbh | Screw compressor |
| CN101014771A (en) * | 2004-03-03 | 2007-08-08 | 雷弗孔普股份有限公司 | Volumetric screw compressor provided with delivery adjustment device |
| CN104500399A (en) * | 2014-09-15 | 2015-04-08 | 汉钟精机股份有限公司 | Compressor slide valve position control structure |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113550902B (en) | 2023-03-31 |
| WO2021213064A1 (en) | 2021-10-28 |
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