A method for controlling a compressor and a compression system

Abstract

The application provides a method for controlling a compressor and a compression system, the method for controlling the compressor comprising: obtaining an exhaust pressure of the compressor; dynamically controlling working modes of a variable frequency compression unit and a fixed frequency compression unit according to the exhaust pressure, so as to regulate the exhaust capacity of the compressor; wherein the working modes at least include a stop working mode, a loading working mode and an unloading working mode, and the variable frequency compression unit and the fixed frequency compression unit are connected with an oil-gas separator to provide compressed gas to the oil-gas separator through cooperation of the variable frequency compression unit and the fixed frequency compression unit. The above method regulates the exhaust capacity of the compressor by controlling the working modes of the variable frequency compression unit and the fixed frequency compression unit, so that the regulation mode of the exhaust capacity is more flexible, and the regulation range of the exhaust capacity can be expanded.

Description

Technical Field

[0001] This invention relates to the field of compressed gas technology, and more particularly to a method for controlling a compressor and a compression system. Background Technology

[0002] An air compressor is a device used to compress gas. Currently, air compressors typically use a compression unit connected to a traditional motor, and each compression unit needs to be connected to a corresponding oil-gas separator for oil-gas separation. This traditional drive system has high energy consumption, low efficiency, and a limited range for adjusting the overall output air volume. Summary of the Invention

[0003] In view of the above-mentioned technical problems existing in the prior art, the present invention provides a method and a compression system for controlling a compressor, which can regulate the discharge volume of the compressor by controlling the working mode of the variable frequency compression unit and the fixed frequency compression unit, making the discharge volume adjustment method more flexible and expanding the adjustment range of the discharge volume.

[0004] This invention provides a method for controlling a compressor, the method comprising:

[0005] Obtain the compressor's discharge pressure;

[0006] The operating modes of the variable frequency compression unit and the fixed frequency compression unit are dynamically controlled based on the exhaust pressure, thereby regulating the exhaust volume of the compressor; wherein,

[0007] The operating modes include at least a stop operating mode, a loading operating mode, and an unloading operating mode. The variable frequency compression unit and the fixed frequency compression unit are respectively connected to the oil-gas separator to provide compressed gas to the oil-gas separator through the cooperation of the variable frequency compression unit and the fixed frequency compression unit.

[0008] In some embodiments, dynamically controlling the operating modes of the variable frequency compression unit and the fixed frequency compression unit based on the exhaust pressure specifically includes:

[0009] When the exhaust pressure is less than the first preset pressure, the variable frequency compression unit is controlled to enter the loading working mode and continue to load, and the fixed frequency compression unit is controlled to enter the stop working mode.

[0010] When the exhaust pressure is greater than or equal to the first preset pressure, both the variable frequency compression unit and the fixed frequency compression unit are controlled to enter the stop working mode.

[0011] In some embodiments, after controlling the variable frequency compression unit to enter a loading working mode and continuously load, the method further includes:

[0012] When the exhaust pressure is greater than or equal to a first preset pressure and less than a fourth preset pressure, the variable frequency compression unit is controlled to maintain the loading operation mode while the fixed frequency compression unit is controlled to enter the stop operation mode; wherein...

[0013] The fourth preset pressure is greater than the first preset pressure.

[0014] In some embodiments, the method further includes:

[0015] When the exhaust pressure is greater than or equal to the fourth preset pressure, the variable frequency compression unit is controlled to enter the unloading working mode, while the fixed frequency compression unit remains in the stop working mode.

[0016] In some embodiments, after controlling the variable frequency compression unit to enter the unloading working mode and the fixed frequency compression unit to remain in the stop working mode, the method further includes:

[0017] Determine whether the exhaust pressure is greater than or equal to the first preset pressure;

[0018] If so, the variable frequency compression unit is controlled to maintain the unloading working mode, and the fixed frequency compression unit is controlled to maintain the stop working mode;

[0019] If not, the variable frequency compression unit is controlled to enter the loading working mode, while the fixed frequency compression unit remains in the stop working mode.

[0020] In some embodiments, after controlling the variable frequency compression unit to maintain an unloaded operating mode and the fixed frequency compression unit to maintain a stop operating mode, the method further includes:

[0021] Determine whether the duration of the variable frequency compression unit maintaining the unloaded working mode exceeds the third preset time;

[0022] If so, both the variable frequency compression unit and the fixed frequency compression unit are controlled to enter the stop working mode.

[0023] In some embodiments, after controlling the variable frequency compression unit to enter a loading working mode and continuously load, the method further includes:

[0024] When the exhaust pressure is less than the second preset pressure, the fixed-frequency compression unit is controlled to enter the unloading mode, while the variable-frequency compression unit remains in the loading mode; or,

[0025] When the exhaust pressure is less than the first preset pressure and greater than the second preset pressure, and the duration exceeds the first preset time, the fixed-frequency compression unit is controlled to enter the unloading working mode, while the variable-frequency compression unit remains in the loading working mode; wherein, the first preset pressure is greater than the second preset pressure.

[0026] In some embodiments, after controlling the fixed-frequency compression unit to enter the unloading working mode, the method further includes:

[0027] Determine whether the exhaust pressure is less than the second preset pressure; or,

[0028] If the exhaust pressure is less than a first preset pressure and the exhaust pressure is greater than or equal to a second preset pressure, and the duration exceeds a first preset time, then...

[0029] If so, the fixed-frequency compression unit is controlled to enter the loading working mode and continue loading, while the variable-frequency compression unit maintains the loading working mode.

[0030] If not, the fixed-frequency compression unit is kept in unloaded mode, and the variable-frequency compression unit is kept in loaded mode.

[0031] In some embodiments, after controlling the fixed-frequency compression unit to enter a loading working mode and continuously load while the variable-frequency compression unit maintains the loading working mode, the method further includes:

[0032] Determine whether the exhaust pressure is greater than or equal to the third preset pressure;

[0033] If so, the fixed-frequency compression unit is controlled to enter the unloading working mode, while the variable-frequency compression unit remains in the loading working mode; wherein,

[0034] The third preset pressure is greater than the first preset pressure.

[0035] In some embodiments, the method further includes:

[0036] Determine whether the exhaust pressure is greater than or equal to the fourth preset pressure;

[0037] If so, the variable frequency compression unit is controlled to enter the unloading working mode, while the fixed frequency compression unit remains in the unloading working mode;

[0038] If not, the fixed-frequency compression unit is controlled to remain in unloaded operating mode, and the variable-frequency compression unit is controlled to remain in loaded operating mode; wherein,

[0039] The fourth preset pressure is greater than the third preset pressure.

[0040] In some embodiments, after controlling the fixed-frequency compression unit to maintain an unloaded operating mode and the variable-frequency compression unit to maintain a loaded operating mode, the method further includes:

[0041] Determine whether the duration for which the fixed-frequency compression unit maintains the unloaded working mode exceeds the second preset time;

[0042] If so, the fixed-frequency compression unit is controlled to enter the stop working mode, while the variable-frequency compression unit remains in the loading working mode.

[0043] In some embodiments, after controlling the variable frequency compression unit to enter the unloading working mode and the fixed frequency compression unit to maintain the unloading working mode, the method further includes:

[0044] Determine whether the exhaust pressure is greater than or equal to the first preset pressure;

[0045] If so, the variable frequency compression unit is controlled to maintain the unloading working mode, and the fixed frequency compression unit is controlled to maintain the unloading working mode.

[0046] If not, the variable frequency compression unit is controlled to enter the loading mode, and the fixed frequency compression unit is controlled to enter the unloading mode.

[0047] In some embodiments, after controlling the variable frequency compression unit to maintain the unloaded operating mode and the fixed frequency compression unit to maintain the unloaded operating mode, the method further includes:

[0048] Determine whether the duration of the variable frequency compression unit maintaining the unloaded working mode exceeds the third preset time;

[0049] If so, both the variable frequency compression unit and the fixed frequency compression unit are controlled to enter the stop working mode.

[0050] In some embodiments, the method further includes:

[0051] Determine whether the exhaust pressure is greater than or equal to the fifth preset pressure;

[0052] If so, then the fixed-frequency compression unit and the variable-frequency compression unit are controlled to enter the stop-start working mode; wherein,

[0053] The fifth preset pressure is greater than the fourth preset pressure.

[0054] In some embodiments, the method further includes:

[0055] When the variable frequency compression unit enters the loading operation mode, the oil-gas mixture discharged from the variable frequency compression unit is separated into gas and oil by the oil-gas separator. The gas is cooled by the aftercooler before being discharged, and the oil is cooled by the oil cooler before returning to the variable frequency compression unit.

[0056] The aftercooler is connected to the oil-gas separator to cool the gas produced by the separation of the oil-gas separator; the oil cooler is connected to both the variable frequency compression unit and the oil-gas separator.

[0057] In some embodiments, the method further includes:

[0058] When the variable frequency compression unit enters the unloading working mode, the oil-gas mixture discharged by the variable frequency compression unit passes through the oil-gas separator and the venting pipeline. The gas in the oil-gas separator is vented through the variable frequency compression unit, and the oil-gas mixture discharged by the variable frequency compression unit is separated by the oil-gas separator to produce oil. The oil is cooled by the oil cooler and then returned to the variable frequency compression unit.

[0059] In some embodiments, the method further includes:

[0060] When the fixed-frequency compression unit enters the loading working mode, the oil-gas mixture discharged by the fixed-frequency compression unit is separated by the oil-gas separator to produce gas, which is then cooled by the aftercooler before being discharged.

[0061] The oil-gas mixture discharged from the fixed-frequency compression unit is separated into liquid oil by the oil-gas separator. This liquid oil is then cooled by an oil cooler before entering the fixed-frequency compression unit.

[0062] The aftercooler is connected to the oil-gas separator to cool the gas produced by the oil-gas separator.

[0063] In some embodiments, the method further includes:

[0064] When the fixed-frequency compression unit enters the unloading mode, the oil-gas mixture discharged from the fixed-frequency compression unit enters the buffer tank, allowing the gas to enter the variable-frequency compression unit via the buffer tank, and allowing the oil to enter the fixed-frequency compression unit via the combination valve; wherein...

[0065] The buffer tank is located between the fixed-frequency compression unit and the oil-gas separator; the combined valve is connected to the oil-gas separator, the buffer tank, the oil cooler, and the oil filter, respectively.

[0066] This invention also provides a compression system, including a compressor and a control device, the control device being configured to perform the above-described method for controlling the compressor.

[0067] In some embodiments, the compressor includes a housing and further includes:

[0068] An oil-gas separator, located inside the housing, is used to separate the oil-gas mixture;

[0069] At least two compression units are disposed within the housing and respectively connected to the oil-gas separator. The at least two compression units are constructed in one of the following forms: both are fixed-frequency compression units, both are variable-frequency compression units, or a combination of fixed-frequency compression units and variable-frequency compression units. The at least two compression units are used to cooperate in providing compressed gas to the oil-gas separator.

[0070] In some embodiments, the at least two compression units are configured as a combination of a fixed-frequency compression unit and a variable-frequency compression unit, wherein a buffer tank is provided between the fixed-frequency compression unit and the oil-gas separator, the buffer tank being used to provide buffering for the fixed-frequency compression unit when it is in an unloaded state.

[0071] In some embodiments, the buffer tank is located between the housing and the oil-gas separator, and is positioned close to the oil-gas separator.

[0072] In some embodiments, the at least two compression units are misaligned within the housing.

[0073] In some embodiments, the at least two compression units are arranged side by side inside the housing.

[0074] In some embodiments, the compressor further includes an aftercooler, a first fan, and a plurality of oil coolers corresponding to the compression unit. The aftercooler and the plurality of oil coolers are arranged side by side, and the first fan is located above the oil coolers and the aftercooler.

[0075] In some embodiments, the compressor further includes an aftercooler, a first fan, and a plurality of oil coolers corresponding to the compression units. The plurality of oil coolers are disposed between the corresponding compression units and the housing. The aftercooler is disposed close to one of the oil coolers. The first fan is disposed on the side of the plurality of oil coolers and the side of the aftercooler away from the housing.

[0076] In some embodiments, a misaligned space is formed between the at least two compression units and the housing, and the oil-gas separator is disposed within the misaligned space.

[0077] In some embodiments, an accommodating space is formed between the at least two compression units and the first side wall of the housing, and the oil-gas separator is disposed within the accommodating space.

[0078] In some embodiments, the compressor further includes an aftercooler and a plurality of oil coolers corresponding to the compression unit, wherein the aftercooler and the oil cooler are arranged side by side in the accommodating space.

[0079] In some embodiments, the compressor further includes an air filter connected to and corresponding to the compression unit, the air filter being disposed inside the housing and corresponding to the air inlet on the housing.

[0080] In some embodiments, the oil-gas separator is disposed near the first side wall of the housing, and the compressor further includes an electrical control cabinet disposed inside the housing and near the second side wall of the housing opposite to the first side wall.

[0081] Compared with the prior art, the beneficial effects of the embodiments of the present invention are as follows: The present invention obtains the discharge pressure of the compressor and dynamically controls the working mode of the variable frequency compression unit and the fixed frequency compression unit based on the discharge pressure to regulate the discharge volume of the compressor, making the discharge volume adjustment method more flexible and expanding the discharge volume adjustment range, thus having the advantages of energy saving and efficiency improvement. Attached Figure Description

[0082] In drawings that are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The same reference numerals with or without letter suffixes may indicate different instances of similar parts. The drawings illustrate various embodiments generally by way of example rather than limitation, and are used, together with the description and claims, to explain the disclosed embodiments. Where appropriate, the same reference numerals are used in all drawings to refer to the same or similar parts. Such embodiments are illustrative and not intended to be exhaustive or exclusive embodiments of the apparatus or method.

[0083] Figure 1 This is a schematic diagram of the working principle of a compressor comprising two compression units according to an embodiment of the present invention;

[0084] Figure 2 This is a schematic diagram of the working principle of a compressor including a fixed-frequency compression unit and a variable-frequency compression unit according to an embodiment of the present invention;

[0085] Figure 3 This is a first flowchart of a method for controlling a compressor according to an embodiment of the present invention;

[0086] Figure 4 This is a second flowchart of a method for controlling a compressor according to an embodiment of the present invention;

[0087] Figure 5 This is a third flowchart of a method for controlling a compressor according to an embodiment of the present invention;

[0088] Figure 6 This is a gas path diagram of a compression system used in an embodiment of the present invention for controlling a compressor. The variable frequency compression unit shown in the diagram is in a loaded working mode, and the fixed frequency compression unit is in an unloaded working mode.

[0089] Figure 7 This is an oil circuit diagram of a compression system used in an embodiment of the present invention for controlling a compressor. The variable frequency compression unit shown in the diagram is in a loaded working mode, and the fixed frequency compression unit is in an unloaded working mode.

[0090] Figure 8 This is a gas path diagram of a compression system used in an embodiment of the present invention for controlling a compressor. Both the variable frequency compression unit and the fixed frequency compression unit shown in the diagram are in a loaded working mode.

[0091] Figure 9 This is an oil circuit diagram of a compression system used in an embodiment of the present invention for controlling a compressor. Both the variable frequency compression unit and the fixed frequency compression unit shown in the diagram are in the loading working mode.

[0092] Figure 10 This is a gas path diagram of a compression system used in an embodiment of the present invention for controlling a compressor. Both the variable frequency compression unit and the fixed frequency compression unit shown in the diagram are in unloading mode.

[0093] Figure 11 This is an oil circuit diagram of a compression system used in an embodiment of the present invention for controlling a compressor. Both the variable frequency compression unit and the fixed frequency compression unit shown in the diagram are in unloading mode.

[0094] Figure 12 This is a schematic diagram of the structure of an air-cooled compressor according to Embodiment 1 of the present invention;

[0095] Figure 13 This is a schematic diagram of the air-cooled compressor according to another perspective of Embodiment 1 of the present invention;

[0096] Figure 14 This is a top view of the air-cooled compressor according to Embodiment 1 of the present invention;

[0097] Figure 15 This is a schematic diagram of the structure of the air-cooled compressor according to Embodiment 2 of the present invention;

[0098] Figure 16 This is a schematic diagram of the air-cooled compressor from another perspective in Embodiment 2 of the present invention;

[0099] Figure 17 This is a top view of the air-cooled compressor according to Embodiment 2 of the present invention;

[0100] Figure 18 This is a schematic diagram of the structure of a water-cooled compressor according to an embodiment of the present invention;

[0101] Figure 19 This is a schematic diagram of the water-cooled compressor from another perspective according to an embodiment of the present invention;

[0102] Figure 20 This is a top view of a water-cooled compressor according to an embodiment of the present invention.

[0103] The components indicated by the reference numerals in the figure:

[0104] 1-Oil-gas separator; 2-Compression unit; 201-Fixed frequency compression unit; 202-Variable frequency compression unit; 3-Intake valve; 4-Buffer tank; 5-Aftercooler; 6-Minimum pressure valve; 7-Air filter; 8-Temperature control valve; 9-Oil cooler; 10-Oil filter; 11-First fan; 12-Electrical control cabinet; 13-Combination valve; 14-Injection valve. Detailed Implementation

[0105] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and specific examples, but this is not intended to limit the present invention.

[0106] The terms "first," "second," and similar words used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "comprising" mean that the element preceding the word encompasses the element listed after it, without excluding the possibility of encompassing other elements. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0107] In this invention, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may be not directly connected to the other devices but have an intermediary device.

[0108] All terms used in this invention (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this invention pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0109] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0110] This invention provides a method for controlling a compressor, which can be applied to a compression system including a compressor, such as... Figure 1 and Figure 2As shown, the compressor includes at least a compression unit 2 and an oil-gas separator 1. The compression unit 2 may include a variable frequency speed regulation device (VSD) and a fixed frequency speed device (FS) connected to the oil-gas separator 1, respectively, to provide compressed gas to the oil-gas separator 1 via the cooperation of the variable frequency speed regulation device 202 and the fixed frequency speed regulation device 201.

[0111] The compressor described above can be configured as an air-cooled compressor or a water-cooled compressor. Figure 1 This is a schematic diagram of the working principle of a compressor that includes two compression units 2. Figure 2 This is a schematic diagram of the working principle of a compressor including a fixed-frequency compression unit 201 and a variable-frequency compression unit 202.

[0112] Furthermore, such as Figure 3 As shown, the method for controlling the compressor includes steps S101 to S102.

[0113] Step S101: Obtain the compressor's discharge pressure;

[0114] Step S102: Dynamically control the working modes of the variable frequency compression unit 202 and the fixed frequency compression unit 201 according to the exhaust pressure, thereby regulating the exhaust volume of the compressor; wherein, the working modes include at least a stop working mode, a loading working mode and an unloading working mode.

[0115] Specifically, the aforementioned exhaust pressure can be understood as any one of the following three gas pressures: the gas pressure discharged from the oil-gas separator 1, the gas pressure at the inlet and outlet of the aftercooler 5, and the gas pressure at the outlet of the compressor. This is a real-time measured value, used to control the operating mode of the variable frequency compression unit 202 and the fixed frequency compression unit 201 based on the real-time exhaust pressure. For example, Figure 1 and Figure 2 As shown, the aftercooler 5 is connected to the outlet of the oil-gas separator 1 and is used to cool the compressed gas separated by the oil-gas separator 1.

[0116] Specifically, the above-mentioned loading and unloading working modes are the working modes that the compression unit 2 has when it is in operation. In addition to the working modes that it has when it is in operation, the above-mentioned working modes may also include the stop working mode when the compression unit 2 stops.

[0117] Specifically, the discharge volume and discharge pressure of the compressor can be understood as having a positive correlation. When the discharge volume increases, the discharge pressure increases accordingly, and when the discharge volume decreases, the discharge pressure decreases accordingly.

[0118] Specifically, controlling the working modes of the variable frequency compression unit 202 and the fixed frequency compression unit 201 can be understood as controlling the variable frequency compression unit 202 and the fixed frequency compression unit 201 to be in different working modes or in the same working mode. In short, the purpose is to adjust the exhaust volume by controlling the working modes of the variable frequency compression unit 202 and the fixed frequency compression unit 201.

[0119] Specifically, at least two compression units 2 are connected to the oil-gas separator 1 respectively. This can be understood as the compression units 2 not being directly connected to each other, but being connected to the oil-gas separator 1 in parallel.

[0120] This invention obtains the discharge pressure of the compressor and dynamically controls the working mode of the variable frequency compression unit 202 and the fixed frequency compression unit 201 based on the discharge pressure to regulate the discharge volume of the compressor. This makes the discharge volume adjustment method more flexible and can expand the adjustment range of the discharge volume, thus having the advantages of energy saving and efficiency improvement.

[0121] In some embodiments, when the compressor is in its initial state, the intake valves 3 connected to each compression unit 2 are closed. After the compressor's control device issues a start command, the compression system using the compressor begins to operate. After operation, the discharge pressure (P) and the first preset pressure (P1) can be compared. The intake valves 3 are connected to the compression units 2 and are configured in a one-to-one correspondence with each compression unit 2, so that the gas entering through the intake valves 3 is compressed by the corresponding compression unit 2 before entering the oil-gas separator 1.

[0122] In some embodiments, such as Figure 4 As shown, step S102, which involves dynamically controlling the operating modes of the variable frequency compression unit 202 and the fixed frequency compression unit 201 based on the exhaust pressure, specifically includes:

[0123] When the exhaust pressure is less than the first preset pressure, the variable frequency compression unit 202 is controlled to enter the loading mode and the fixed frequency compression unit 201 is controlled to enter the stop mode. That is, when P < P1, the compression system is in standby mode, the variable frequency compression unit 202 enters the loading mode, and the fixed frequency compression unit 201 enters the stop mode.

[0124] Specifically, the first preset pressure mentioned above can be understood as a set value, which can be set based on experience or obtained from experimental conclusions. This application does not specifically limit it in this regard. The second preset pressure (P2), third preset pressure (P3), fourth preset pressure (P4), and fifth preset pressure (P5) mentioned below are also set values.

[0125] In some embodiments, further combined Figure 4When the exhaust pressure is greater than or equal to the first preset pressure, both the variable frequency compression unit 202 and the fixed frequency compression unit 201 are controlled to enter the stop working mode.

[0126] In some embodiments, such as Figure 4 As shown, after controlling the variable frequency compression unit 202 to enter the loading working mode and controlling the fixed frequency compression unit 201 to enter the stop working mode, the method further includes:

[0127] When the exhaust pressure is greater than or equal to the fourth preset pressure (P4), the variable frequency compression unit 202 is controlled to enter the unloading working mode, and the fixed frequency compression unit 201 remains in the stop working mode, wherein the fourth preset pressure is greater than the first preset pressure; when the exhaust pressure is less than the fourth preset pressure, it is determined whether P1≤P<P4, or whether P<P2, or whether P2≤P≤P1 is satisfied and continues for a first preset time (T1).

[0128] That is, when P≥P4, the variable frequency compression unit 202 enters the unloading working mode, and the fixed frequency compression unit 201 remains in the stop working mode; when P<P4, it is determined whether P1≤P<P4, or whether P<P2, or whether P2≤P≤P1 is satisfied and continues for T1.

[0129] In some embodiments, such as Figure 4 As shown, step S102, which involves dynamically controlling the operating modes of the variable frequency compression unit 202 and the fixed frequency compression unit 201 based on the exhaust pressure, specifically includes:

[0130] When the exhaust pressure is less than the first preset pressure (P1), the variable frequency compression unit 202 is controlled to enter the loading working mode and continuously load; the fixed frequency compression unit 201 is controlled to enter the stop working mode. That is, when P < P1, the variable frequency compression unit 202 starts, enters the loading working mode and continuously loads;

[0131] When the exhaust pressure is greater than or equal to a first preset pressure, both the variable frequency compression unit 202 and the fixed frequency compression unit 201 are controlled to enter a stop-operation mode. That is, when P≥P1, both the variable frequency compression unit 202 and the fixed frequency compression unit 201 are controlled to enter a stop-operation mode.

[0132] Specifically, when the exhaust pressure is less than the first preset pressure, the variable frequency compression unit 202 can start its variable frequency motor at the lowest speed, and after a certain delay, the variable frequency compression unit 202 enters the loading working mode.

[0133] In some embodiments, such as Figure 4As shown, after controlling the variable frequency compression unit 202 to enter the loading working mode and continuously load, the method further includes:

[0134] When the exhaust pressure is greater than or equal to a first preset pressure and less than a fourth preset pressure, the variable frequency compression unit 202 is controlled to maintain the loading operation mode and the fixed frequency compression unit 201 is controlled to enter the stop operation mode; wherein, the fourth preset pressure is greater than the first preset pressure. That is, when P1≤P<P4, the variable frequency compression unit 202 is controlled to maintain the loading operation mode and the fixed frequency compression unit 201 is controlled to enter the stop operation mode.

[0135] In some embodiments, such as Figure 4 As shown, the method further includes: when the exhaust pressure is greater than or equal to a fourth preset pressure, controlling the variable frequency compression unit 202 to enter the unloading working mode, while the fixed frequency compression unit 201 remains in the stop working mode. That is, when P≥P4, the variable frequency compression unit 202 enters the unloading working mode, while the fixed frequency compression unit 201 remains in the stop working mode.

[0136] In some embodiments, such as Figure 4 As shown, after controlling the variable frequency compression unit to enter the unloading working mode and the fixed frequency compression unit 201 to remain in the stop working mode, the method further includes:

[0137] Determine whether the exhaust pressure is greater than or equal to the first preset pressure;

[0138] If so, the variable frequency compression unit 202 is controlled to maintain the unloading working mode, and the fixed frequency compression unit 201 is controlled to maintain the stop working mode;

[0139] If not, the variable frequency compression unit 202 is controlled to enter the loading working mode, while the fixed frequency compression unit 201 remains in the stop working mode.

[0140] That is, when P≥P1, the variable frequency compression unit 202 maintains the unloading working mode, and the fixed frequency compression unit 201 maintains the stop working mode; when P<P1, the variable frequency compression unit 202 enters the loading working mode, and the fixed frequency compression unit 201 maintains the stop working mode.

[0141] In some embodiments, such as Figure 4 As shown, after controlling the variable frequency compression unit 202 to maintain the unloading working mode and the fixed frequency compression unit 201 to maintain the stop working mode, the method further includes:

[0142] Determine whether the duration of the variable frequency compression unit 202 maintaining the unloading working mode exceeds the third preset time (T3);

[0143] If so, both the variable frequency compression unit 202 and the fixed frequency compression unit 201 are controlled to enter the stop-start working mode. After both the variable frequency compression unit 202 and the fixed frequency compression unit 201 are controlled to enter the stop-start working mode, the compressor system restarts its automatic operation.

[0144] In some embodiments, such as Figure 4 As shown, after controlling the variable frequency compression unit to enter the loading working mode and continuously load, the method further includes:

[0145] When the exhaust pressure is less than the second preset pressure, the fixed-frequency compression unit 201 is controlled to enter the unloading mode, while the variable-frequency compression unit 202 remains in the loading mode; or,

[0146] When the exhaust pressure is less than the first preset pressure and greater than the second preset pressure, and the duration exceeds the first preset time (T1), the fixed-frequency compression unit 201 is controlled to enter the unloading working mode, and the variable-frequency compression unit 202 remains in the loading working mode; wherein, the first preset pressure is greater than the second preset pressure.

[0147] That is, when P < P2 or P2 ≤ P < P1, and this condition is maintained for T1, the fixed-frequency compression unit 201 enters the unloading working mode, while the variable-frequency compression unit 202 remains in the loading working mode.

[0148] In some embodiments, such as Figure 4 As shown, after controlling the fixed-frequency compression unit 201 to enter the unloading working mode, the method further includes:

[0149] Determine whether the exhaust pressure is less than the second preset pressure; or,

[0150] If the exhaust pressure is less than a first preset pressure and the exhaust pressure is greater than or equal to a second preset pressure, and the duration exceeds a first preset time, then...

[0151] If so, the fixed-frequency compression unit 201 is controlled to enter the loading working mode and continue loading, while the variable-frequency compression unit 202 maintains the loading working mode.

[0152] If not, the fixed-frequency compression unit 201 is controlled to remain in unloaded working mode, and the variable-frequency compression unit 202 is controlled to remain in loaded working mode.

[0153] That is, when P < P2 or P2 ≤ P < P1, and this condition is maintained for T1, the fixed-frequency compression unit 201 enters the loading working mode and continues to load, while the variable-frequency compression unit 202 maintains the loading working mode.

[0154] In some embodiments, such as Figure 4As shown, after controlling the fixed-frequency compression unit 201 to enter the loading working mode and continuously load while the variable-frequency compression unit 202 maintains the loading working mode, the method further includes:

[0155] Determine whether the exhaust pressure is greater than or equal to the third preset pressure;

[0156] If so, the fixed-frequency compression unit 201 is controlled to enter the unloading working mode, while the variable-frequency compression unit 202 remains in the loading working mode;

[0157] If not, the fixed-frequency compression unit 201 and the variable-frequency compression unit 202 maintain the loading operation mode. The third preset pressure is greater than the first preset pressure.

[0158] That is, when P≥P3, the fixed-frequency compression unit 201 enters the unloading working mode, while the variable-frequency compression unit 202 remains in the loading working mode; when P<P3, both the fixed-frequency compression unit 201 and the variable-frequency compression unit 202 remain in the loading working mode.

[0159] In some embodiments, such as Figure 4 As shown, the method further includes:

[0160] Determine whether the exhaust pressure is greater than or equal to the fourth preset pressure;

[0161] If so, the variable frequency compression unit 202 is controlled to enter the unloading working mode, while the fixed frequency compression unit 201 remains in the unloading working mode;

[0162] If not, the fixed-frequency compression unit 201 is controlled to maintain the unloading working mode, and the variable-frequency compression unit 202 is controlled to maintain the loading working mode; wherein, the fourth preset pressure is greater than the third preset pressure.

[0163] That is, when P≥P4, the variable frequency compression unit 202 enters the unloading working mode, while the fixed frequency compression unit 201 remains in the unloading working mode.

[0164] In some embodiments, such as Figure 4 As shown, after controlling the fixed-frequency compression unit 201 to maintain the unloading working mode and the variable-frequency compression unit 202 to maintain the loading working mode, the method further includes:

[0165] Determine whether the duration of the fixed-frequency compression unit 201 maintaining the unloading working mode exceeds the second preset time (T2);

[0166] If so, the fixed-frequency compression unit 201 is controlled to enter the stop working mode, while the variable-frequency compression unit 202 remains in the loading working mode;

[0167] If not, the fixed-frequency compression unit 201 is controlled to remain in unloaded working mode, and the variable-frequency compression unit 202 is controlled to remain in loaded working mode.

[0168] Specifically, the first preset time, the second preset time, and the third preset time may be the same time, or they may be different times, or any two of the three may be the same time. This application does not make any specific limitation in this regard.

[0169] In some embodiments, such as Figure 4 As shown, after controlling the variable frequency compression unit 202 to enter the unloading working mode and the fixed frequency compression unit 201 to maintain the unloading working mode, the method further includes:

[0170] Determine whether the exhaust pressure is greater than or equal to the first preset pressure;

[0171] If so, the variable frequency compression unit 202 is controlled to maintain the unloading working mode, and the fixed frequency compression unit 201 is controlled to maintain the unloading working mode.

[0172] If not, the variable frequency compression unit 202 is controlled to enter the loading working mode, and the fixed frequency compression unit 201 is controlled to enter the unloading working mode.

[0173] That is, when P≥P1, the variable frequency compression unit 202 maintains the unloading working mode, and the fixed frequency compression unit 201 maintains the unloading working mode; when P<P1, the variable frequency compression unit 202 enters the loading working mode, and the fixed frequency compression unit 201 enters the unloading working mode.

[0174] In some embodiments, such as Figure 4 As shown, after controlling the variable frequency compression unit 202 to maintain the unloaded working mode and the fixed frequency compression unit 201 to maintain the unloaded working mode, the method further includes:

[0175] Determine whether the duration of the variable frequency compression unit 202 maintaining the unloading working mode exceeds the third preset time;

[0176] If so, then both the variable frequency compression unit 202 and the fixed frequency compression unit 201 are controlled to enter the stop working mode;

[0177] If not, the fixed-frequency compression unit 201 is controlled to maintain the unloading working mode, and the variable-frequency compression unit 202 is controlled to maintain the unloading working mode.

[0178] In some embodiments, such as Figure 5 As shown, the method further includes:

[0179] Determine whether the exhaust pressure is greater than or equal to the fifth preset pressure (P5);

[0180] If so, then control the fixed-frequency compression unit 201 and the variable-frequency compression unit 202 to enter the stop-start working mode;

[0181] If not: the control system continues to operate as described above. The fifth preset pressure is greater than the fourth preset pressure.

[0182] That is, when P≥P5, the fixed-frequency compression unit 201 and the variable-frequency compression unit 202 enter the stop-and-go working mode; when P<P5, the control system continues to operate as described above, that is, it continues to make judgments.

[0183] In some embodiments, such as Figures 6 to 9 As shown, the method further includes: when the variable frequency compression unit 202 enters the loading working mode, the oil-gas mixture discharged by the variable frequency compression unit 202 is separated into gas and oil by the oil-gas separator 1. The gas is cooled by the aftercooler 5 and then discharged, and the oil is cooled by the oil cooler 9 and then returned to the variable frequency compression unit 202; wherein, the aftercooler 5 is connected to the oil-gas separator 1 to cool the gas separated by the oil-gas separator 1; the oil cooler 9 is connected to both the variable frequency compression unit 202 and the oil-gas separator 1.

[0184] Specifically, part of the gas generated by the oil-gas separator 1 is cooled by the aftercooler 5 and discharged, while the other part enters the variable frequency compression unit 202 to open the intake valve 3 connected to it.

[0185] Specifically, a portion of the oil flows sequentially through the temperature control valve 8, oil cooler 9, and oil filter 10 corresponding to the variable frequency compression unit 202 before entering the variable frequency compression unit 202. The other portion is directly drawn back into the variable frequency compression unit 202 by the oil-gas separator 1 under the action of the variable frequency compression unit 202. The temperature control valve 8 is connected to the bottom of the oil-gas separator 1 and the compression unit 2, respectively, and is used to control the oil temperature of the oil entering the compression unit 2 after separation by the oil-gas separator 1. The oil cooler 9 is used to cool the oil entering the compression unit 2 through the temperature control valve 8. The oil filter 10 is located between the oil cooler 9 and the compression unit 2, and is used to filter the oil cooled by the oil cooler 9 before it enters the compression unit 2.

[0186] Specifically, the aforementioned temperature control valve 8, oil cooler 9, and oil filter 10 are respectively provided in a one-to-one correspondence with the compression unit 2. The compressor may also include a first fan 11, which is used to exchange heat with the oil cooler 9 and the aftercooler 5 through external gas.

[0187] Specifically, the minimum pressure valve 6 is located at the outlet of the oil-gas separator 1, and the aftercooler 5 is connected to the oil-gas separator 1 through the minimum pressure valve 6. The minimum pressure valve 6 is used to keep the gas pressure in the oil-gas separator 1 within a preset threshold.

[0188] Specifically, the temperature control valve 8, oil cooler 9 and oil filter 10 corresponding to the variable frequency compression unit 202 are connected in sequence, and the temperature control valve 8 is connected to the bottom of the oil-gas separator 1, and the oil filter 10 is connected to the variable frequency compression unit 202.

[0189] In some embodiments, such as Figure 10 and Figure 11 As shown, the method further includes:

[0190] When the variable frequency compression unit 202 enters the unloading working mode, the oil-gas mixture discharged by the variable frequency compression unit 202 passes through the oil-gas separator 1 and the venting pipeline, and the gas in the oil-gas separator 1 is vented through the variable frequency compression unit 202. The oil-gas mixture discharged by the variable frequency compression unit 202 is separated by the oil-gas separator 1 to produce oil. The oil is cooled by the oil cooler 9 and then returned to the variable frequency compression unit 202.

[0191] Specifically, a portion of the oil flows sequentially through the temperature control valve 8, oil cooler 9, and oil filter 10 corresponding to the variable frequency compression unit 202 before entering the variable frequency compression unit 202, while the other portion is directly drawn back into the variable frequency compression unit 202 by the oil-gas separator 1 under the action of the variable frequency compression unit 202.

[0192] Specifically, the exhaust gas from the aforementioned variable frequency compression unit 202 is discharged through the intake valve 3 located upstream of the variable frequency compression unit 202.

[0193] In some embodiments, such as Figure 8 and Figure 9 As shown, the method further includes:

[0194] When the fixed-frequency compression unit 201 enters the loading working mode, the oil-gas mixture discharged by the fixed-frequency compression unit 201 is separated by the oil-gas separator 1 to generate gas, which is then cooled by the aftercooler 5 before being discharged.

[0195] The oil-gas mixture discharged from the fixed-frequency compression unit 201 is separated into oil by the oil-gas separator 1. The oil is cooled by the oil cooler 9 and then enters the fixed-frequency compression unit 201. The aftercooler 5 is connected to the oil-gas separator 1 to cool the gas separated by the oil-gas separator 1.

[0196] Specifically, the minimum pressure valve 6 is located at the outlet of the oil-gas separator 1, and the aftercooler 5 is connected to the minimum pressure valve 6 to discharge the gas generated by the oil-gas separator 1.

[0197] Specifically, the oil flows sequentially through the temperature control valve 8, oil cooler 9, and oil filter 10 corresponding to the fixed-frequency compression unit 201 before entering the fixed-frequency compression unit 201.

[0198] In some embodiments, such as Figure 6 , Figure 7 , Figure 10 as well as Figure 11 As shown, the method further includes:

[0199] When the fixed-frequency compression unit 201 enters the unloading working mode, the oil-gas mixture discharged from the fixed-frequency compression unit 201 enters the buffer tank 4, allowing the gas to enter the variable-frequency compression unit 202 via the buffer tank 4, and allowing the oil to enter the fixed-frequency compression unit 201 via the combination valve 13; wherein...

[0200] The buffer tank 4 is located between the fixed-frequency compression unit 201 and the oil-gas separator 1, and is positioned close to the oil-gas separator 1.

[0201] Specifically, the buffer tank 4 is used to provide buffering for the fixed-frequency compression unit 201 when it is in the unloaded state, and the combination valve 13 is connected to the oil-gas separator 1, the buffer tank 4, the oil cooler 9 and the oil filter 10 respectively.

[0202] In some embodiments, such as Figure 9 As shown, the method further includes:

[0203] When the fixed-frequency compression unit 201 enters the loading working mode, the oil-gas mixture discharged from the fixed-frequency compression unit 201 is separated into oil by the oil-gas separator 1. This oil then flows sequentially through the temperature control valve 8, oil cooler 9, and oil filter 10 corresponding to the fixed-frequency compression unit 201 before entering the fixed-frequency compression unit 201.

[0204] The temperature control valve 8, oil cooler 9 and oil filter 10 corresponding to the fixed frequency compression unit 201 are connected in sequence, and the temperature control valve 8 is connected to the bottom of the oil-gas separator 1, and the oil filter 10 is connected to the fixed frequency compression unit 201.

[0205] In some embodiments, the oil-gas separator 1 is disposed near the first side wall of the housing, and the compressor further includes an electrical control cabinet 12, which is disposed inside the housing and near the second side wall of the housing opposite to the first side wall.

[0206] In some embodiments, the compressor further includes an air filter 7 connected to and corresponding to the compression unit 2, the air filter 7 being located at the air inlet of the housing.

[0207] In some embodiments, such as Figures 6 to 11 As shown, the variable frequency compression unit 202 and the fixed frequency compression unit 201 can be connected by an oil pipe. The oil pipe is equipped with an oil injection valve 14, which is used to introduce the oil in the variable frequency compression unit 202 into the fixed frequency compression unit 201.

[0208] This invention also provides a compression system, including a compressor and a control device, wherein the control device is configured to execute the above-described method for controlling the compressor. The compression system using the above-described compressor obtains the compressor's discharge pressure and dynamically controls the operating modes of the variable frequency compression unit 202 and the fixed frequency compression unit 201 based on the discharge pressure to regulate the compressor's discharge volume. This makes the discharge volume adjustment method more flexible and expands the discharge volume adjustment range, thus possessing the advantages of energy saving and efficiency improvement.

[0209] In some embodiments, such as Figures 12 to 20 As shown, the compressor includes a housing (not shown), an oil-gas separator 1, and at least two compression units 2. The oil-gas separator 1 is located inside the housing and is used to separate the oil-gas mixture. At least two compression units 2 are located inside the housing and are respectively connected to the oil-gas separator 1. The at least two compression units 2 are constructed in one of the following forms: both are fixed-frequency compression units 201, both are variable-frequency compression units 202, or a combination of fixed-frequency compression units 201 and variable-frequency compression units 202. The at least two compression units 2 are used to cooperate in supplying compressed gas to the oil-gas separator 1.

[0210] The compressor described above can be configured as an air-cooled compressor or a water-cooled compressor. Figures 12 to 14 This is a structural diagram of the air-cooled compressor in Example 1. Figures 15 to 17 This is a structural diagram of the air-cooled compressor in Example 2. Figures 18 to 20 This is a structural diagram of a water-cooled compressor.

[0211] Specifically, such as Figure 12 and Figure 14 As shown, the air-cooled compressor in Embodiment 1 includes two compression units 2, namely a fixed-frequency compression unit 201 and a variable-frequency compression unit 202. The two compression units 2 are respectively connected to the oil-gas separator 1, thereby cooperating to provide compressed gas to the oil-gas separator 1.

[0212] Specifically, such as Figure 15 and Figure 17As shown, Embodiment 2 is another air-cooled compressor including two compression units 2, namely a fixed-frequency compression unit 201 and a variable-frequency compression unit 202. The two compression units 2 are respectively connected to the oil-gas separator 1, thereby cooperating to provide compressed gas to the oil-gas separator 1.

[0213] Specifically, such as Figure 18 and Figure 20 As shown, the water-cooled compressor includes two compression units 2, namely a fixed-frequency compression unit 201 and a variable-frequency compression unit 202. The two compression units 2 are respectively connected to the oil-gas separator 1, thereby cooperating to provide compressed gas to the oil-gas separator 1.

[0214] Specifically, at least two compression units 2 are connected to the oil-gas separator 1 respectively. This can be understood as the compression units 2 not being directly connected to each other, but being connected to the oil-gas separator 1 in parallel.

[0215] Specifically, the aforementioned housing can be constructed as a rectangular housing, or of other shapes, such as a hexagonal housing. This housing is used to cover the oil-gas separator 1 and the compression unit 2, serving as the outer casing of the entire machine.

[0216] When the gas-consuming end corresponding to the compressor is operating at full load, at least two compression units 2 can meet the requirements of simultaneous start-up, operation, and shutdown. When the gas-consuming end requires a smaller amount of gas, some of the at least two compression units 2 can be stopped, and the gas volume can be adjusted by the other operating compression units 2. For example, when at least two compression units 2 are configured as a combination of a fixed-frequency compression unit 201 and a variable-frequency compression unit 202, the operation of the fixed-frequency compression unit 201 can be stopped, and the gas volume can be adjusted by the variable-frequency compression unit 202.

[0217] This invention utilizes at least two compression units 2 respectively connected to an oil-gas separator 1. By cooperating with each of the at least two compression units 2 to supply compressed gas to the oil-gas separator 1, the energy consumption of the compressor is lower than that of a compressor containing a single compression unit 2, thus reducing energy consumption. Furthermore, the multiple compression units 2 are respectively connected to the oil-gas separator 1, which reduces the product size compared to setting multiple oil-gas separators 1, thereby optimizing the overall size of the compressor and reducing manufacturing costs.

[0218] In some embodiments, such as Figures 12 to 20 As shown, at least two compression units 2 are configured as a combination of a fixed-frequency compression unit 201 and a variable-frequency compression unit 202. A buffer tank 4 is provided between the fixed-frequency compression unit 201 and the oil-gas separator 1. The buffer tank 4 is used to provide buffer for the fixed-frequency compression unit 201 when it is in an unloaded state.

[0219] Specifically, both the oil-gas separator 1 and the buffer tank 4 are constructed as cylindrical tanks, and the volume of the oil-gas separator 1 is larger than the volume of the buffer tank 4.

[0220] In some embodiments, such as Figure 14 and Figure 20 As shown, the buffer tank 4 is located between the housing and the oil-gas separator 1, and is positioned close to the oil-gas separator 1.

[0221] Specifically, when the above-mentioned box structure is a rectangular box, the buffer tank 4 is located at one of the corners of the rectangular box.

[0222] In some embodiments, such as Figures 12 to 17 As shown, at least two compression units 2 of the air-cooled compressor in Embodiment 1 and the air-cooled compressor in Embodiment 2 are staggered and arranged in the housing.

[0223] Specifically, Figures 12 to 17 The compression unit 2 shown is two, with one compression unit 2 positioned opposite the other near the first side wall of the housing. The first side wall of the housing can be understood as... Figure 13 It is located on the left side wall near the oil-gas separator 1.

[0224] In some embodiments, such as Figures 12 to 14 As shown, the air-cooled compressor in Embodiment 1 also includes an aftercooler 5, a first fan 11, and multiple oil coolers 9 corresponding one-to-one with the compression unit 2. The aftercooler 5 and the multiple oil coolers 9 are arranged side by side. The first fan 11 is located above the oil coolers 9 and the aftercooler 5. The first fan 5 can be configured as a single large fan or as multiple small fans arranged side by side. This design results in a compact structure and a reasonable layout.

[0225] Specifically, such as Figure 1 and Figure 2 As shown, the aftercooler 5 is connected to the outlet of the oil-gas separator 1 and is used to cool the compressed gas separated by the oil-gas separator 1.

[0226] Specifically, such as Figure 1 and Figure 2 As shown, the compressor may also include multiple temperature control valves 8, each corresponding to a compression unit 2. The temperature control valves 8 are connected to the bottom of the oil-gas separator 1 and the compression unit 2, respectively. The temperature control valves 8 are used to control the oil temperature of the oil entering the compression unit 2 after separation by the oil-gas separator 1. An oil cooler 9 is located between the temperature control valves 8 and the compression unit 2, and is used to cool the oil entering the compression unit 2 through the temperature control valves 8.

[0227] Specifically, such as Figure 1 and Figure 2As shown, the compressor may also include an oil filter 10, which is located between the oil cooler 9 and the compression unit 2, and is used to filter the oil cooled by the oil cooler 9 before it enters the compression unit 2.

[0228] Specifically, the first fan 11 is used to exchange heat with the oil cooler 9 and the aftercooler 5 through external gas.

[0229] In some embodiments, such as Figures 15 to 17 As shown, the air-cooled compressor in Embodiment 1 also includes an aftercooler 5, a first fan 11, and multiple oil coolers 9 corresponding to the compression units 2. The multiple oil coolers 9 are disposed between the corresponding compression units 2 and the housing. The aftercooler 5 is positioned close to one of the oil coolers 9. The first fan 11 is positioned on the side of the multiple oil coolers 9 and the aftercooler 5 away from the housing, so as to exchange heat between the external gas and the oil coolers 9 and the aftercooler 5.

[0230] In some embodiments, such as Figures 12 to 17 As shown, in both the air-cooled compressor of Embodiment 1 and the air-cooled compressor of Embodiment 2, at least two compression units 2 form a misaligned space with the housing, and the oil-gas separator 1 is located within the misaligned space. This design results in a compact structure and a reasonable layout.

[0231] Specifically, such as Figure 14 and Figure 17 As shown, the two compression units 2 and the first side wall of the box form the aforementioned misaligned space.

[0232] In some embodiments, such as Figures 18 to 20 As shown, at least two compression units 2 are arranged side by side inside the housing.

[0233] In some embodiments, such as Figure 20 As shown, at least two compression units 2 of the water-cooled compressor form an accommodating space between themselves and the first side wall of the housing, and the oil-gas separator 1 is located within this accommodating space. This design results in a compact structure and a reasonable layout.

[0234] Specifically, the water-cooled compressor includes a fixed-frequency compression unit 201 and a variable-frequency compression unit 202. A buffer tank 4 is provided between the fixed-frequency compression unit 201 and the oil-gas separator 1. The buffer tank 4 is located within the aforementioned accommodating space.

[0235] In some embodiments, such as Figure 20 As shown, the compressor also includes an aftercooler 5 and multiple oil coolers 9, each corresponding to a compression unit 2. The aftercooler 5 and the oil coolers 9 are arranged side by side in the accommodating space. This design results in a compact structure and a reasonable layout.

[0236] In some embodiments, such as Figures 12 to 20As shown, the compressor also includes an air filter 7 connected to and corresponding to the compression unit 2. The air filter 7 is located inside the housing and is positioned corresponding to the air inlet on the housing. The air filter 7 is used to filter impurities in the gas entering the compression unit 2.

[0237] Specifically, the air filters 7 are all located above their corresponding compression units 2.

[0238] In some embodiments, such as Figures 12 to 20 As shown, the oil-gas separator 1 is located near the first side wall of the housing, and the compressor also includes an electrical control cabinet 12, which is located inside the housing and near the second side wall of the housing opposite to the first side wall.

[0239] In some embodiments, such as Figure 1 , Figure 2 as well as Figures 12 to 20 As shown, the compressor also includes an intake valve 3, which is connected to the compression unit 2 and is configured in a one-to-one correspondence with each compression unit 2, so that the gas entering through the intake valve 3 is compressed by the corresponding compression unit 2 and then enters the oil-gas separator 1.

[0240] In some embodiments, such as Figure 1 and Figure 2 As shown, the compressor also includes a minimum pressure valve 6 located at the outlet of the oil-gas separator 1. The aftercooler 5 is connected to the oil-gas separator 1 through the minimum pressure valve 6. The minimum pressure valve 6 is used to keep the gas pressure in the oil-gas separator 1 within a preset threshold.

[0241] The compressor's operating process is described below: External gas enters the compression unit 2 sequentially through the air filter 7 and the intake valve 3. The compressed gas from the compression unit 2 enters the oil-gas separator 1 through the inlet corresponding to each compression unit 2. After the oil-gas mixture is separated by the oil-gas separator 1, the resulting gas is discharged to the user end sequentially through the minimum pressure valve 6 and the aftercooler 5. The user end is the end that requires compressed gas from the compressor. The oil produced by the oil-gas separator 1 flows through the temperature control valve 8 corresponding to each compression unit 2. The oil is adjusted to a suitable temperature by the temperature control valve 8 and cooled by the oil cooler 9. Then, it is discharged to each compression unit 2 for recycling after passing through the oil filter 10.

[0242] Furthermore, although exemplary embodiments have been described herein, their scope includes any and all embodiments based on the invention that have equivalent elements, modifications, omissions, combinations (e.g., schemes involving intersections of various embodiments), adaptations, or alterations. Elements in the claims will be interpreted broadly based on the language used in the claims and are not limited to the examples described in this specification or during the implementation of this application, and such examples will be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered illustrative only, and the true scope and spirit are indicated by the following claims and the full scope of their equivalents.

[0243] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more of them) can be used in combination with each other. Other embodiments can be used by those skilled in the art when reading the above description. Furthermore, in the above detailed description, various features may be grouped together to simplify the invention. This should not be construed as an intention that a disclosed feature, which is not claimed, is necessary for any claim. Rather, the subject matter of the invention may be less than all the features of the particular disclosed embodiments. Thus, the following claims are incorporated herein by reference as examples or embodiments, wherein each claim is independently considered as a separate embodiment, and these embodiments are contemplated as being able to be combined with each other in various combinations or arrangements. The scope of the invention should be determined by reference to the appended claims and the full scope of their equivalents.

[0244] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. A method for controlling a compressor, characterized in that, The method includes: Obtain the compressor's discharge pressure; The operating modes of the variable frequency compression unit and the fixed frequency compression unit are dynamically controlled based on the exhaust pressure, thereby regulating the exhaust volume of the compressor; wherein, The operating modes include at least a stop-and-go operating mode, a loading operating mode, and an unloading operating mode. The variable-frequency compression unit and the fixed-frequency compression unit are respectively connected to the oil-gas separator to provide compressed gas to the oil-gas separator through their cooperation. The method further includes: When the fixed-frequency compression unit enters the unloading working mode, the oil-gas mixture discharged from the fixed-frequency compression unit enters the buffer tank, and the gas enters the variable-frequency compression unit through the buffer tank.

2. The method for controlling a compressor according to claim 1, characterized in that, The method of dynamically controlling the operating modes of the variable frequency compression unit and the fixed frequency compression unit based on the exhaust pressure specifically includes: When the exhaust pressure is less than the first preset pressure, the variable frequency compression unit is controlled to enter the loading working mode and continue to load, and the fixed frequency compression unit is controlled to enter the stop working mode. When the exhaust pressure is greater than or equal to the first preset pressure, both the variable frequency compression unit and the fixed frequency compression unit are controlled to enter the stop working mode.

3. The method for controlling a compressor according to claim 2, characterized in that, After controlling the variable frequency compression unit to enter the loading working mode and continuously load, the method further includes: When the exhaust pressure is greater than or equal to a first preset pressure and less than a fourth preset pressure, the variable frequency compression unit is controlled to maintain the loading operation mode while the fixed frequency compression unit is controlled to enter the stop operation mode; wherein... The fourth preset pressure is greater than the first preset pressure.

4. The method for controlling a compressor according to claim 2 or 3, characterized in that, The method further includes: When the exhaust pressure is greater than or equal to the fourth preset pressure, the variable frequency compression unit is controlled to enter the unloading working mode, while the fixed frequency compression unit remains in the stop working mode.

5. The method for controlling a compressor according to claim 4, characterized in that, After controlling the variable frequency compression unit to enter the unloading working mode and the fixed frequency compression unit to remain in the stop working mode, the method further includes: Determine whether the exhaust pressure is greater than or equal to the first preset pressure; If so, the variable frequency compression unit is controlled to maintain the unloading working mode, and the fixed frequency compression unit is controlled to maintain the stop working mode; If not, the variable frequency compression unit is controlled to enter the loading working mode, while the fixed frequency compression unit remains in the stop working mode.

6. The method for controlling a compressor according to claim 5, characterized in that, After controlling the variable frequency compression unit to maintain the unloading working mode and the fixed frequency compression unit to maintain the stop working mode, the method further includes: Determine whether the duration of the variable frequency compression unit maintaining the unloaded working mode exceeds the third preset time; If so, both the variable frequency compression unit and the fixed frequency compression unit are controlled to enter the stop working mode.

7. The method for controlling a compressor according to claim 2, characterized in that, After controlling the variable frequency compression unit to enter the loading working mode and continuously load, the method further includes: When the exhaust pressure is less than the second preset pressure, the fixed-frequency compression unit is controlled to enter the unloading mode, while the variable-frequency compression unit remains in the loading mode; or, When the exhaust pressure is less than the first preset pressure and greater than the second preset pressure, and the duration exceeds the first preset time, the fixed-frequency compression unit is controlled to enter the unloading working mode, while the variable-frequency compression unit remains in the loading working mode; wherein, the first preset pressure is greater than the second preset pressure.

8. The method for controlling a compressor according to claim 7, characterized in that, After controlling the fixed-frequency compression unit to enter the unloading working mode, the method further includes: Determine whether the exhaust pressure is less than the second preset pressure; or, If the exhaust pressure is less than a first preset pressure and the exhaust pressure is greater than or equal to a second preset pressure, and the duration exceeds a first preset time, then... If so, the fixed-frequency compression unit is controlled to enter the loading working mode and continue loading, while the variable-frequency compression unit maintains the loading working mode. If not, the fixed-frequency compression unit is kept in unloaded mode, and the variable-frequency compression unit is kept in loaded mode.

9. The method for controlling a compressor according to claim 8, characterized in that, After controlling the fixed-frequency compression unit to enter the loading working mode and continuously load, and the variable-frequency compression unit to maintain the loading working mode, the method further includes: Determine whether the exhaust pressure is greater than or equal to the third preset pressure; If so, the fixed-frequency compression unit is controlled to enter the unloading working mode, while the variable-frequency compression unit remains in the loading working mode; wherein, The third preset pressure is greater than the first preset pressure.

10. The method for controlling a compressor according to claim 9, characterized in that, The method further includes: Determine whether the exhaust pressure is greater than or equal to the fourth preset pressure; If so, the variable frequency compression unit is controlled to enter the unloading working mode, while the fixed frequency compression unit remains in the unloading working mode; If not, the fixed-frequency compression unit is controlled to remain in unloaded operating mode, and the variable-frequency compression unit is controlled to remain in loaded operating mode; wherein, The fourth preset pressure is greater than the third preset pressure.

11. The method for controlling a compressor according to claim 8 or 10, characterized in that, After controlling the fixed-frequency compression unit to maintain the unloaded operating mode and the variable-frequency compression unit to maintain the loaded operating mode, the method further includes: Determine whether the duration for which the fixed-frequency compression unit maintains the unloaded working mode exceeds the second preset time; If so, the fixed-frequency compression unit is controlled to enter the stop working mode, while the variable-frequency compression unit remains in the loading working mode.

12. The method for controlling a compressor according to claim 10, characterized in that, After controlling the variable frequency compression unit to enter the unloading working mode and the fixed frequency compression unit to maintain the unloading working mode, the method further includes: Determine whether the exhaust pressure is greater than or equal to the first preset pressure; If so, the variable frequency compression unit is controlled to maintain the unloading working mode, and the fixed frequency compression unit is controlled to maintain the unloading working mode. If not, the variable frequency compression unit is controlled to enter the loading mode, and the fixed frequency compression unit is controlled to enter the unloading mode.

13. The method for controlling a compressor according to claim 12, characterized in that, After controlling the variable frequency compression unit to maintain the unloaded operating mode and the fixed frequency compression unit to maintain the unloaded operating mode, the method further includes: Determine whether the duration of the variable frequency compression unit maintaining the unloaded working mode exceeds the third preset time; If so, both the variable frequency compression unit and the fixed frequency compression unit are controlled to enter the stop working mode.

14. The method for controlling a compressor according to claim 3 or 10, characterized in that, The method further includes: Determine whether the exhaust pressure is greater than or equal to the fifth preset pressure; If so, then the fixed-frequency compression unit and the variable-frequency compression unit are controlled to enter the stop-start working mode; wherein, The fifth preset pressure is greater than the fourth preset pressure.

15. The method for controlling a compressor according to claim 1, characterized in that, The method further includes: When the variable frequency compression unit enters the loading operation mode, the oil-gas mixture discharged from the variable frequency compression unit is separated into gas and oil by the oil-gas separator. The gas is cooled by the aftercooler before being discharged, and the oil is cooled by the oil cooler before returning to the variable frequency compression unit. The aftercooler is connected to the oil-gas separator to cool the gas produced by the separation of the oil-gas separator; the oil cooler is connected to both the variable frequency compression unit and the oil-gas separator.

16. The method for controlling a compressor according to claim 1, characterized in that, The method further includes: When the variable frequency compression unit enters the unloading working mode, the oil-gas mixture discharged by the variable frequency compression unit passes through the oil-gas separator and the venting pipeline. The gas in the oil-gas separator is vented through the variable frequency compression unit, and the oil-gas mixture discharged by the variable frequency compression unit is separated by the oil-gas separator to produce oil. The oil is cooled by the oil cooler and then returned to the variable frequency compression unit.

17. The method for controlling a compressor according to claim 15, characterized in that, The method further includes: When the fixed-frequency compression unit enters the loading working mode, the oil-gas mixture discharged by the fixed-frequency compression unit is separated by the oil-gas separator to produce gas, which is then cooled by the aftercooler before being discharged. The oil-gas mixture discharged from the fixed-frequency compression unit is separated into liquid oil by the oil-gas separator. This liquid oil is then cooled by an oil cooler before entering the fixed-frequency compression unit. The aftercooler is connected to the oil-gas separator to cool the gas produced by the oil-gas separator.

18. The method for controlling a compressor according to any one of claims 1 and 15-16, characterized in that, The method further includes: When the fixed-frequency compression unit enters the unloading mode, the oil-gas mixture discharged from the fixed-frequency compression unit enters the buffer tank, allowing the oil to enter the fixed-frequency compression unit via the combination valve; wherein... The buffer tank is located between the fixed-frequency compression unit and the oil-gas separator, and the combined valve is connected to the oil-gas separator, the buffer tank, the oil cooler, and the oil filter, respectively.

19. A compression system, characterized in that, It includes a compressor and a control device, the control device being configured to perform a method for controlling the compressor as claimed in any one of claims 1-18.

20. The compression system according to claim 19, characterized in that, The compressor includes a housing and also includes: An oil-gas separator, located inside the housing, is used to separate the oil-gas mixture; At least two compression units are disposed within the housing and respectively connected to the oil-gas separator. The at least two compression units are configured as a combination of a fixed-frequency compression unit and a variable-frequency compression unit. The at least two compression units are used to cooperate in providing compressed gas to the oil-gas separator.

21. The compression system according to claim 20, characterized in that, The at least two compression units are configured as a combination of a fixed-frequency compression unit and a variable-frequency compression unit, wherein a buffer tank is provided between the fixed-frequency compression unit and the oil-gas separator, and the buffer tank is used to provide buffer for the fixed-frequency compression unit when it is in an unloaded state.

22. The compression system according to claim 21, characterized in that, The buffer tank is located between the housing and the oil-gas separator, and is positioned close to the oil-gas separator.

23. The compression system according to claim 20, characterized in that, The at least two compression units are misaligned within the housing.

24. The compression system according to claim 20, characterized in that, The at least two compression units are arranged side by side inside the housing.

25. The compression system according to claim 23, characterized in that, The compressor also includes an aftercooler, a first fan, and a plurality of oil coolers that are arranged one-to-one with the compression unit. The aftercooler and the plurality of oil coolers are arranged side by side, and the first fan is located above the oil cooler and the aftercooler.

26. The compression system according to claim 23, characterized in that, The compressor also includes an aftercooler, a first fan, and a plurality of oil coolers that are arranged one-to-one with the compression unit. The plurality of oil coolers are arranged between the compression unit and the housing, and the aftercooler is arranged close to one of the oil coolers. The first fan is arranged one-to-one with the side of the plurality of oil coolers and the side of the aftercooler away from the housing.

27. The compression system according to claim 23, characterized in that, A misaligned space is formed between the at least two compression units and the housing, and the oil-gas separator is located within the misaligned space.

28. The compression system according to claim 24, characterized in that, An accommodating space is formed between the at least two compression units and the first side wall of the housing, and the oil-gas separator is disposed within the accommodating space.

29. The compression system according to claim 28, characterized in that, The compressor also includes an aftercooler and a plurality of oil coolers that are arranged one-to-one with the compression unit. The aftercooler and the oil cooler are arranged in parallel in the accommodating space.

30. The compression system according to claim 20, characterized in that, The compressor also includes an air filter connected to and corresponding to the compression unit, the air filter being disposed inside the housing and corresponding to the air inlet on the housing.

31. The compression system according to claim 20, characterized in that, The oil-gas separator is located near the first side wall of the housing, and the compressor also includes an electrical control cabinet, which is located inside the housing and near the second side wall of the housing opposite to the first side wall.

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