Compressor system

Abstract

The utility model provides a compressor system. The compressor system includes a first compressor, a second compressor, and an oil balance pipe. The first compressor and the second compressor are arranged in parallel. An oil pool of the first compressor is communicated with an oil pool of the second compressor through an oil balance pipe. The first compressor is provided with a monitoring device used for monitoring lubricating oil in an oil pool of the first compressor. The second compressor is provided with a protection device for stopping the second compressor when the second compressor runs abnormally. And the monitoring device is in communication connection with the protection device, so that the protection device can respond to a signal that the monitoring value of the lubricating oil exceeds a preset range to stop the second compressor. According to the compressor system, lubricating oil balance is achieved through the protection device of the second compressor, so that an additional or special control device does not need to be designed or manufactured, the structure and operation of the compressor system are simplified, and the cost of the compressor system is reduced.

Description

Technical Field

[0001] The present application relates to a compressor system including at least two compressors and an operating method of the compressor system. Background Art

[0002] The contents of this section merely provide background information related to the present application and may not constitute prior art.

[0003] Compressor systems consisting of two or more compressors connected in parallel are known. Such compressor systems can utilize multiple compressors with relatively small refrigeration capacity to replace a single compressor with large refrigeration capacity to meet larger system capacity requirements, thereby reducing system costs and improving system overall efficiency.

[0004] In this compressor system, a variable frequency compressor is usually included. The variable frequency compressor operates within a wide operating frequency range (or speed range), which can easily lead to an imbalance in cooling capacity with other compressors, and thus an imbalance in lubricating oil between compressors. For example, when the variable frequency compressor operates at a low speed, the oil return capacity is poor, causing the oil level to decrease. When the oil level is lower than the safe oil level, some components will wear out or even fail due to insufficient lubricating oil supply.

[0005] A solution for solving the problem of lubricating oil imbalance is known, which includes a control device configured to achieve lubricating oil balance between compressors by controlling the operating state of at least one compressor (e.g., high speed or low speed operation, shutdown, etc.) according to a predetermined control logic or after detecting that a compressor lacks lubricating oil. The control device is usually installed in a compressor system and stops the compressor by cutting off the power supply to the compressor. Utility Model Content

[0006] The conventional compressor system as described above has an additional or separate control device for achieving lubricating oil balance, so its structure, installation or operation is complicated and the cost is high.

[0007] In view of the above-mentioned problems of the existing compressor system, the present application proposes a solution for achieving lubricating oil balance between various compressors, which has simple structure, installation or operation and low cost.

[0008] According to one aspect of the present application, a compressor system is provided. The compressor system includes a first compressor, a second compressor and an oil balance pipe. The first compressor and the second compressor are arranged in parallel. The oil pool of the first compressor is connected to the oil pool of the second compressor through the oil balance pipe. The first compressor is provided with a monitoring device for monitoring the lubricating oil in the oil pool of the first compressor. The second compressor has a protection device for shutting down the second compressor when the operation of the second compressor is abnormal. The monitoring device is communicatively connected to the protection device so that the protection device can shut down the second compressor in response to a signal that the monitoring value of the lubricating oil exceeds a predetermined range.

[0009] The compressor system of the present application utilizes the protection device of the second compressor itself (i.e., the shutdown protection part provided when designing the second compressor) to achieve lubricating oil balance, so there is no need to design or manufacture additional or dedicated control devices, thereby simplifying the structure and operation process of the oil balance control and reducing costs.

[0010] In some embodiments of the compressor system, the monitoring device comprises an oil level sensor for sensing an oil level. The protection device is configured to shut down the second compressor in response to a signal indicating that the sensed oil level is lower than a first predetermined oil level.

[0011] In some embodiments of the compressor system, the monitoring device comprises a temperature sensor for sensing oil temperature. The protection device is configured to shut down the second compressor in response to a signal indicating that the sensed oil temperature is higher than a first predetermined oil temperature.

[0012] In some embodiments of the compressor system, the protection device is configured to restart the second compressor when the following conditions are met: the sensed oil level rises to a second predetermined oil level, wherein the second predetermined oil level is higher than or equal to the first predetermined oil level; or a predetermined time has passed after the second compressor is shut down.

[0013] In some embodiments of the compressor system, the protection device is configured to restart the second compressor when the following conditions are met: the sensed oil temperature drops to a second predetermined oil temperature, wherein the second predetermined oil temperature is lower than or equal to the first predetermined oil temperature; or a predetermined time has passed after the second compressor is shut down.

[0014] In some embodiments of the compressor system, the monitoring device is configured to compare the monitoring value with the predetermined range, determine whether the monitoring value exceeds the predetermined range based on the comparison result, and send a signal to the protection device when it is determined that the monitoring value exceeds the predetermined range.

[0015] In some embodiments of the compressor system, the monitoring device is communicatively connected to the protection device in a wired or wireless manner.

[0016] In some embodiments of the compressor system, the first compressor is a variable frequency compressor, and the second compressor is a fixed frequency compressor.

[0017] In some embodiments of the compressor system, the protection device is configured to stop the motor when the compressed working fluid in the second compressor exceeds a predetermined temperature or a predetermined pressure, wherein the motor is configured to drive a compression mechanism of the second compressor.

[0018] According to another aspect of the present disclosure, a method for operating a compressor system is provided. The compressor system includes a first compressor and a second compressor connected in parallel and an oil balance pipe, the oil pool of the first compressor is connected to the oil pool of the second compressor through the oil balance pipe, and the second compressor has a protection device that shuts down the second compressor when the operation of the second compressor is abnormal. The operating method includes: monitoring the lubricating oil in the oil pool of the first compressor by a monitoring device; making the monitoring device communicate with the protection device, so that the protection device can shut down the second compressor in response to a signal that the monitoring value of the lubricating oil exceeds a predetermined range.

[0019] In some embodiments of the operating method, the monitoring device comprises an oil level sensor for sensing the oil level. When receiving a signal that the sensed oil level is lower than a first predetermined oil level, the protection device stops the second compressor.

[0020] In some embodiments of the operating method, the monitoring device includes a temperature sensor for sensing oil temperature. When receiving a signal indicating that the sensed oil temperature is higher than a first predetermined oil temperature, the protection device stops the second compressor.

[0021] In some embodiments of the operating method, it also includes restarting the second compressor through the protection device when the following conditions are met: sensing that the oil level of the lubricating oil has risen to a second predetermined oil level, wherein the second predetermined oil level is higher than or equal to the first predetermined oil level; or a predetermined time has passed after the second compressor is shut down.

[0022] In some embodiments of the operating method, it also includes restarting the second compressor through the protection device when the following conditions are met: sensing that the oil temperature of the lubricating oil drops to a second predetermined oil temperature, wherein the second predetermined oil temperature is lower than or equal to the first predetermined oil temperature; or a predetermined time has passed after the second compressor is shut down.

[0023] In some embodiments of the operating method, it also includes: in the monitoring device, comparing the monitoring value with the predetermined range, judging whether the monitoring value exceeds the predetermined range based on the comparison result, and sending a signal to the protection device when it is determined that the monitoring value exceeds the predetermined range.

[0024] In some embodiments of the operating method, the monitoring device sends a signal to the protection device in a wired or wireless manner.

[0025] In some embodiments of the operating method, the first compressor is a variable frequency compressor, and the second compressor is a fixed frequency compressor.

[0026] In some embodiments of the operating method, it also includes: when the compressed working fluid in the second compressor exceeds a predetermined temperature or a predetermined pressure, stopping the motor through the protection device, wherein the motor is configured to drive the compression mechanism of the second compressor.

[0027] The operating method of the compressor system according to the present application has the same or corresponding advantages as the compressor system according to the present application.

[0028] Other areas of applicability will become apparent from the description provided herein.It should be understood that the specific examples and implementations described in this section are for illustrative purposes only and are not intended to limit the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The features and advantages of one or more embodiments of the present disclosure will become more easily understood through the following description with reference to the accompanying drawings, in which:

[0030] Figure 1A and Figure 1B They are respectively a front view schematic diagram and a rear view schematic diagram of a compressor system according to an embodiment of the present disclosure;

[0031] Figure 2 is a flow chart of an operating method of a compressor system according to an embodiment of the present disclosure;

[0032] Figure 3 is a flow chart of an operating method of a compressor system according to another embodiment of the present disclosure; and

[0033] Figure 4 It is a flow chart of an operating method of a compressor system according to yet another embodiment of the present disclosure. DETAILED DESCRIPTION

[0034] Exemplary embodiments of the present application will now be described more fully with reference to the accompanying drawings. It should be understood that throughout all of the drawings, like reference numerals indicate similar or corresponding parts or features.

[0035] Exemplary embodiments are provided so that the present disclosure will be exhaustive and will more fully convey the scope to those skilled in the art. Many specific details such as examples of specific components, devices, and methods are set forth to provide a thorough understanding of the various embodiments of the present disclosure. It will be clear to those skilled in the art that specific details need not be employed, that the exemplary embodiments can be implemented in many different forms, and that they should not be construed as limiting the scope of the present disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0036] See below for more information. Figure 1A and Figure 1B A schematic diagram of a compressor system 1 according to an embodiment of the present disclosure is described. Figure 1A and Figure 1B They are respectively a front view schematic diagram and a rear view schematic diagram of the compressor system 1. Figure 1A and Figure 1B As shown, the compressor system 1 includes a first compressor 10 and a second compressor 20. The first compressor 10 and the second compressor 20 are connected in parallel.

[0037] The first compressor 10 includes a compressor body 12, an intake pipe 11 and an exhaust pipe 13 connected to the compressor body 12, and a protection device (also referred to as a "protection module") 15. When the first compressor 10 is running, a working fluid (e.g., a refrigerant) enters the compressor body 12 via the intake pipe 11, is compressed by a compression mechanism (not shown) of the first compressor 10, and then is discharged from the exhaust pipe 13 and enters other components (e.g., a heat exchanger as a condenser) (not shown) of the compressor system 1.

[0038] The protection device 15 is used to shut down the first compressor 10 when the operation of the first compressor 10 is abnormal, thereby protecting the first compressor 10. The "protection device" described herein refers to a device or module that is designed or shipped with the compressor for shutting down the compressor to protect the compressor when it is abnormally operated. For example, when the first compressor 10 is overheated or overloaded, the protection device 15 is activated to shut down the first compressor 10. Typically, a sensor (not shown) for sensing parameters such as temperature, pressure or current of the compressed working fluid is provided in the first compressor 10, and when the sensed value exceeds a predetermined value, the protection device 15 stops the motor (not shown). The motor drives the movable scroll (not shown) of the compression mechanism via a drive shaft (not shown), so that the movable scroll revolves relative to the fixed scroll to compress the working fluid.

[0039] The second compressor 20 includes a compressor body 22, an intake pipe 21 and an exhaust pipe 23 connected to the compressor body 22, and a protection device (also referred to as a "protection module") 25. When the second compressor 20 is running, the working fluid enters the compressor body 22 via the intake pipe 21, is compressed by the compression mechanism (not shown) of the second compressor 20, and then is discharged from the exhaust pipe 23 and enters other components (e.g., a heat exchanger as a condenser) (not shown) of the compressor system 1.

[0040] The function of the protection device 25 is similar to that of the protection device 15, that is, it is used to stop the second compressor 20 when the operation of the second compressor 20 is abnormal, thereby protecting the second compressor 20. For example, when the second compressor 20 is overheated or overloaded, the protection device 25 is activated to stop the second compressor 20. Generally, a sensor (not shown) for sensing parameters such as temperature or pressure of the compressed working fluid is provided in the second compressor 20, and when the sensed value exceeds a predetermined value, the protection device 25 stops the motor (not shown). The motor drives the movable scroll (not shown) of the compression mechanism via a drive shaft (not shown), so that the movable scroll revolves relative to the fixed scroll to compress the working fluid.

[0041] The intake pipe 11 of the first compressor 10 and the intake pipe 21 of the second compressor 20 are connected to the intake manifold 40. The low-temperature and low-pressure working fluid flows from the intake manifold 40 into the intake pipe 11 and the intake pipe 21, respectively, and thereby enters the first compressor body 12 and the second compressor body 22, respectively.

[0042] The exhaust pipe 13 of the first compressor 10 and the exhaust pipe 23 of the second compressor 20 are connected to the exhaust manifold 30. The compressed high-temperature and high-pressure working fluid is discharged to the exhaust manifold 30 through the exhaust pipe 13 and the exhaust pipe 23, respectively, and then discharged to the compressor system 1 through the exhaust manifold 30.

[0043] The first compressor 10 and the second compressor 20 connected in parallel can meet the larger system capacity requirements. During the operation of the compressor system 1, the lubricating oil will circulate in the compressor system 1 along with the working fluid. However, due to the different types, operating parameters or working conditions of the compressors in the compressor system, the distribution of the working fluid is different, resulting in different oil return capabilities. For example, when the lubricating oil contained in the working fluid entering the compressor body 12 or 22 through the intake pipe 11 or 21 is less than the lubricating oil contained in the working fluid discharged through the exhaust pipe 13 or 23, the oil level of the oil pool in the compressor 10 or 20 will become lower and lower, eventually resulting in insufficient lubricating oil. In addition, when the operating cooling capacity of the two compressors is different, the pressure inside the shell of each compressor will be different, so that the lubricating oil will flow from the compressor with a higher pressure inside the shell to the compressor with a lower pressure inside the shell through the oil balance pipe under the action of the pressure difference, thereby resulting in insufficient lubricating oil in the compressor with a higher pressure inside the shell. When the lubricating oil is insufficient, the wear of the moving parts will be aggravated, and even premature failure will occur.

[0044] The term "oil return capability" is generally used to reflect the ability to return lubricating oil to the compressor. In other words, during the operation of the compressor system, if one compressor can return more lubricating oil to its oil pool, the oil return capability of the compressor is better or higher, while the other compressor returns less lubricating oil to its oil pool, the oil return capability of the compressor is poor or lower.

[0045] The compressor system according to the present application proposes an oil balancing solution with simplified structure, installation or operation and low cost. The compressor system according to the present application is described below by taking the first compressor 10 as a variable frequency compressor and the second compressor 20 as a fixed frequency compressor (also referred to as a "fixed speed compressor") as an example. When the displacement of the variable frequency compressor is small, especially when the variable frequency compressor is running at a low speed, the oil return capacity of the variable frequency compressor is poor or low, while the oil return capacity of the fixed frequency compressor is good or high. In addition, when the pressure inside the casing of the variable frequency compressor is greater than the pressure inside the casing of the fixed frequency compressor, the lubricating oil inside the casing of the variable frequency compressor will flow to the fixed frequency compressor via the oil balancing pipe. However, it should be understood that the utility model should not be limited to the specific examples of the compressor systems shown in the figures or described herein, but is applicable to any suitable compressor system with oil imbalance problems.

[0046] The compressor system 1 further includes an oil balance pipe 50. The oil balance pipe 50 is configured to connect the oil pool of the first compressor 10 (e.g., the bottom of the compressor body 12) with the oil pool of the second compressor 20 (e.g., the bottom of the compressor body 22). Thus, under the effect of the pressure difference between the first compressor 10 and the second compressor 20, the lubricating oil can flow between the first compressor 10 and the second compressor 20.

[0047] The first compressor 10 includes a monitoring device 17 for monitoring the lubricating oil in the oil sump of the first compressor 10. The monitoring device 17 is Figure 1A . The monitoring device 17 may vary according to different detection parameters of the lubricating oil. In one example, the monitoring device 17 may be configured to monitor the liquid level of the lubricating oil (also referred to herein as the "oil level"), and for this purpose may include an oil level sensor for measuring the oil level. In another example, the monitoring device 17 may be configured to monitor the temperature of the lubricating oil (also referred to herein as the "oil temperature"), and for this purpose may include a temperature sensor for measuring the oil temperature. The monitoring device 17 may directly sense or measure the parameters of the lubricating oil through a sensor. In an alternative example, the monitoring device 17 may also indirectly monitor or obtain the parameters of the lubricating oil. For example, the monitoring device 17 may include a timer for timing the operation of the first compressor 10. The condition of the lubricating oil, such as whether there is a lack of oil or the oil level, etc., can be roughly judged based on the rotational speed and operating time of the first compressor 10.

[0048] It should be understood that the monitoring device 17 is configured to monitor the condition of the lubricating oil directly or indirectly, and should not be limited to the specific examples described herein. The "monitoring" described herein includes both "direct sensing or measurement" and "indirect inference or judgment".

[0049] The monitoring device 17 of the first compressor 10 is communicatively connected to the protection device 25 of the second compressor 20. The monitoring device 17 can communicate directly or indirectly with the protection device 25, so that the protection device 25 can shut down the second compressor 20 in response to a signal that the monitoring value of the lubricating oil exceeds a predetermined range. The monitoring device 17 can be communicatively connected to the protection device 25 in a wired or wireless manner known in the art.

[0050] In one example, the monitoring device 17 can be configured to process a signal of a monitoring value representing the lubricating oil, determine whether the measured value exceeds a predetermined range, and send a trigger signal (or alarm signal) or instruction to shut down the second compressor 20 to the protection device 25 when it is determined that the monitoring value exceeds the predetermined range.

[0051] In another example, the monitoring device 17 may directly send a signal representing the monitoring value of the lubricating oil to the protection device 25. The protection device 25 may process the signal and determine whether the monitoring value exceeds a predetermined range, and shut down the second compressor 20 when the monitoring value exceeds the predetermined range.

[0052] The "predetermined range" mentioned herein refers to the expected range in which the lubricant meets the demand. When the monitored value exceeds the predetermined range (ie, is outside the predetermined range), it indicates that the lubricant cannot meet the demand at this time.

[0053] After the second compressor 20 is shut down, the pressure in the second compressor 20 is higher than the pressure in the first compressor 10. Therefore, under the effect of the pressure difference between the second compressor 20 and the first compressor 10, the lubricating oil in the second compressor 20 flows into the first compressor 10 via the oil balance pipe 50. In this way, the lubricating oil in the first compressor 10 gradually increases, thereby avoiding premature failure of components due to lack of oil.

[0054] The compressor system 1 according to the present application utilizes the protection device 25 of the second compressor 20 itself to shut down the second compressor 20 to compensate for the lubricating oil of the first compressor 10. In other words, the compressor system according to the present application utilizes the shutdown protection part of one of the compressors that can shut it down to achieve the balance between the compressors. Therefore, the compressor system according to the present application does not need to design or set up additional or special control devices or modules to achieve the balance of lubricating oil between the compressors. "Additional or special control device" refers to a device or module that is independent of the compressor's own protection device (or protection module), or in other words, a device or module that is unrelated to the compressor's own protection device (or protection module). The structure and operation of the compressor system according to the present application are significantly simplified, and its cost is also significantly reduced.

[0055] Figures 2 to 4 1 is a flow chart of various embodiments of the method for operating the compressor system according to the present application. Figures 2 to 4 There are different ways to monitor lubricating oil. Figures 2 to 4 Various embodiments of methods of operating a compressor system are described.

[0056] exist Figure 2 In the example shown, the monitoring device 17 of the first compressor 10 comprises an oil level sensor for monitoring the oil level of an oil sump. Figure 2 An operating method 100 for achieving oil balance by monitoring the oil level is shown. Figure 2 As shown, at step S110, the oil level sensor of the monitoring device 17 continuously monitors the oil level of the first compressor 10, for example, continuously monitors at predetermined time intervals. At step S120, the monitoring device 17 compares the measured oil level with the first predetermined oil level, and determines whether the measured oil level is lower than the first predetermined oil level based on the comparison result.

[0057] If the measured oil level is not lower than the first predetermined oil level, it indicates that the first compressor 10 is still in a state of sufficient lubricating oil, and the process returns to step S110 to continue monitoring the oil level of the first compressor 10. If the measured oil level is lower than the first predetermined oil level, it indicates that the first compressor 10 is in a state of insufficient lubricating oil, and the process proceeds to step S130 to perform oil balance adjustment.

[0058] At step S130, the monitoring device 17 sends a signal to the protection device 25 of the second compressor 20 indicating that the measured oil level is lower than the first predetermined oil level. The signal may also be referred to as a trigger signal or an alarm signal for shutting down the second compressor 20. The protection device 25 shuts down the second compressor 20 in response to the signal, see step S140. After the second compressor 20 is shut down, the pressure in the second compressor 20 increases and is higher than the pressure in the first compressor 10, so that the lubricating oil of the second compressor 20 is forced to flow into the first compressor 10 via the oil balance pipe 50 under the pressure difference. The oil level in the first compressor 10 will increase. The oil level of the first compressor 10 continues to be monitored during the shutdown of the second compressor 20, see step S150.

[0059] At step S160, the monitoring device 17 compares the measured oil level with the second predetermined oil level, and determines whether the measured oil level reaches the second predetermined oil level according to the comparison result. The second predetermined oil level can be equal to the first predetermined oil level, or can be greater than the first predetermined oil level to further ensure the adequacy of the lubricating oil.

[0060] If it is determined at step S160 that the measured oil level has not reached the second predetermined oil level, the process returns to step S140, and the second compressor is still in the shutdown state. If it is determined at step S160 that the measured oil level has risen to the second predetermined oil level, the process proceeds to step S170. At step S170, the second compressor 20 is restarted.

[0061] The following will refer to Figure 3 A method 200 for operating a compressor system according to the present application is described. Figure 3 The operating method 200 shown is similar to Figure 2 The difference between the operating method 100 shown is that the judgment condition for restarting the second compressor 20 is different. Figure 3 , steps S210 to S240 of the operating method 200 are respectively the same as steps S110 to S140 of the operating method 100 , and thus will not be described in detail.

[0062] like Figure 3 As shown, after the second compressor 20 is stopped at step S240, due to the pressure difference between the first compressor 10 and the second compressor 20, the lubricating oil will flow from the second compressor 20 into the first compressor 10, so that the oil level in the first compressor 10 gradually rises.

[0063] At step S250, the shutdown time of the second compressor 20 is timed. When the shutdown time of the second compressor reaches a predetermined time (for example, 25 minutes), the process proceeds to step S260 to restart the second compressor 20.

[0064] The following will refer to Figure 4The operating method 300 of the compressor system according to the present application is described. Figure 4 In the example shown, the monitoring device 17 of the first compressor 10 comprises a temperature sensor for monitoring the oil temperature. Figure 4 An operating method 300 for achieving oil balance by monitoring oil temperature is shown. Figure 4 As shown, at step S310, the temperature sensor of the monitoring device 17 continuously monitors the oil temperature of the first compressor 10, for example, continuously monitors at predetermined time intervals. At step S320, the monitoring device 17 compares the measured oil temperature with the first predetermined oil temperature, and determines whether the measured oil temperature is higher than the first predetermined oil temperature based on the comparison result.

[0065] If the measured oil temperature is not higher than the first predetermined oil temperature, the process returns to step S310 to continue monitoring the oil temperature of the first compressor 10. If the measured oil temperature is higher than the first predetermined oil temperature, the process proceeds to step S330 to perform oil balance adjustment.

[0066] At step S330, the monitoring device 17 sends a signal to the protection device 25 of the second compressor 20 indicating that the measured oil temperature is higher than the first predetermined oil temperature. The signal may also be referred to as an alarm signal, and the protection device 25 shuts down the second compressor 20 in response to the signal, see step S340. After the second compressor 20 shuts down, the lubricating oil of the second compressor 20 is forced to flow into the first compressor 10 via the oil balance pipe 50 under the pressure difference. The oil level in the first compressor 10 will rise. The oil temperature of the first compressor 10 continues to be monitored during the shutdown of the second compressor 20, see step S350.

[0067] At step S360, the monitoring device 17 compares the measured oil temperature with the second predetermined oil temperature, and determines whether the measured oil temperature drops to the second predetermined oil temperature according to the comparison result. The second predetermined oil temperature may be equal to the first predetermined oil temperature, or may be less than the first predetermined oil temperature to further ensure the adequacy of the lubricating oil.

[0068] If it is determined at step S360 that the measured oil temperature has not dropped to the second predetermined oil temperature, the process returns to step S340, and the second compressor is still in the shutdown state. If it is determined at step S360 that the measured oil temperature has dropped to the second predetermined oil temperature, the process proceeds to step S370. At step S370, the second compressor 20 is restarted.

[0069] Terms such as “predetermined oil level”, “predetermined oil temperature”, “predetermined time”, etc. in this document can be determined based on historical data or empirical data and pre-stored in the compressor system 1, for example, in the monitoring device 17.

[0070] It should be understood that the operation method of the compressor system according to the present application should not be limited to the specific examples described or shown herein, but can be changed as needed. For example, the monitoring value of the lubricating oil of the first compressor 10 can be directly sent to the protection device 25 of the second compressor 20, and the protection device 25 determines whether the second compressor 20 needs to be shut down.

[0071] The operating method of the compressor system according to the present application may have the same or corresponding advantages as those of the above-mentioned compressor system 1 , and thus will not be described in detail here.

[0072] Although various embodiments of the present invention have been described in detail herein, it should be understood that the present invention is not limited to the specific embodiments described and shown in detail herein, and other variations and modifications may be implemented by those skilled in the art without departing from the essential spirit and scope of the present invention. For example, the steps in the various embodiments may be combined with each other without contradiction. For example, as required, certain steps of the operating method of the compressor system of the present application may be omitted, or other steps known in the prior art may be added. All of these variations and modifications fall within the scope of the present invention.

Claims

1. A compressor system, comprising: The first compressor; a second compressor, the first compressor and the second compressor being arranged in parallel; as well as an oil balance pipe, through which the oil pool of the first compressor is connected to the oil pool of the second compressor, It is characterized in that The first compressor is provided with a monitoring device for monitoring the lubricating oil in the oil pool of the first compressor; The second compressor has a protection device for shutting down the second compressor when the second compressor operates abnormally; The monitoring device is communicatively connected to the protection device so that the protection device can shut down the second compressor in response to a signal that a monitored value of the lubricating oil exceeds a predetermined range.

2. The compressor system according to claim 1, characterized in that The monitoring device comprises an oil level sensor for sensing the oil level, The protection device is configured to shut down the second compressor in response to a signal that the sensed oil level is below a first predetermined oil level.

3. The compressor system according to claim 1, characterized in that The monitoring device includes a temperature sensor for sensing oil temperature, The protection device is configured to shut down the second compressor in response to a signal that the sensed oil temperature is higher than a first predetermined oil temperature.

4. The compressor system according to claim 2, characterized in that The protection device is configured to restart the second compressor when the following conditions are met: the sensed oil level rises to a second predetermined oil level, wherein the second predetermined oil level is higher than or equal to the first predetermined oil level; or A predetermined time elapses after the second compressor is stopped.

5. The compressor system according to claim 3, characterized in that The protection device is configured to restart the second compressor when the following conditions are met: the sensed oil temperature drops to a second predetermined oil temperature, wherein the second predetermined oil temperature is lower than or equal to the first predetermined oil temperature; or A predetermined time elapses after the second compressor is stopped.

6. The compressor system according to any one of claims 1 to 5, characterized in that The monitoring device is communicatively connected to the protection device in a wired or wireless manner.

7. The compressor system according to any one of claims 1 to 5, characterized in that The first compressor is a variable frequency compressor, and the second compressor is a fixed frequency compressor.

8. The compressor system according to any one of claims 1 to 5, characterized in that The protection device is configured to stop the motor from operating when the compressed working fluid in the second compressor exceeds a predetermined temperature or a predetermined pressure, wherein the motor is configured to drive a compression mechanism of the second compressor.

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