Scroll compressor and control method

Abstract

The application provides a scroll compressor and a control method. The compressor comprises a static scroll, a dynamic scroll, an induction unit and a magnetic unit. The static scroll and the dynamic scroll cooperate to form a compression chamber. Two ends of the magnetic unit are respectively communicated with the compression chamber and a suction chamber of the compressor. The magnetic unit is oppositely arranged with the induction unit. When a pressure difference between the compression chamber and the suction chamber meets a threshold condition, the magnetic valve body is located in an induction range of the induction unit, and the induction unit is in a first state. When the pressure difference between the compression chamber and the suction chamber does not meet the threshold condition, the magnetic valve body is located outside the induction range of the induction unit, and the induction unit is in a second state. The compressor provided by the application is provided with a protection device. The protection device is arranged to control the position of the magnetic unit by using the pressure difference between the compression chamber and the suction chamber. The position of the magnetic unit is determined by the state of the induction unit. The running state of the compressor is determined by combining the state of the induction unit and the state of the compressor. On this basis, the running parameters of the compressor are controlled to prevent failure.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and more specifically, to a scroll compressor and its control method. Background Technology

[0002] Existing compressors may experience low-pressure vacuum during operation due to refrigerant leaks, pipe blockages, accidental valve closures, or lack of heat exchange in the heat exchanger, without corresponding protective measures. This low-pressure vacuum environment can easily lead to localized high temperatures in the compressor due to insufficient oil and poor cooling, causing abnormal wear of compressor components and ultimately failure. Furthermore, a low-pressure vacuum environment can also cause high-voltage discharges that damage the motor insulation, resulting in insulation problems.

[0003] When the compressor experiences low system oil circulation rate, no suction flow, excessive pressure ratio, or excessive suction superheat, the discharge temperature will be too high, the lubricating oil viscosity will decrease or even carbonize, increasing leakage in the compression chamber, reducing the compressor's lifespan, and in severe cases, causing dry wear damage to the scroll plate.

[0004] In one existing technical solution, when the compressor is used in an automotive air conditioning system, a three-state pressure switch (usually installed after the condenser) is configured in the system. When refrigerant leakage reaches a certain level and the high-pressure level falls below a certain threshold (e.g., 0.296 MPa), the pressure switch can shut down the compressor, thus preventing wear and failure. The drawback of this solution is that when the refrigeration system does not experience pipe blockage or valve closure due to significant refrigerant leakage, the high-pressure side three-state pressure switch will not activate to protect the compressor because the discharge side pressure remains above the threshold.

[0005] Another existing technical solution is to use a pressure sensor or low-pressure switch at the compressor inlet of the refrigeration pipeline. This can execute a speed reduction or shutdown command when the compressor suction pressure is low, thus protecting the compressor. Alternatively, a pressure sensor or switch can be installed on the low-pressure pipeline of the refrigeration system. When the low-pressure value falls below a certain threshold for a certain period of time, the compressor will shut down. The disadvantages of these solutions are that compressor protection relies on pressure sensors / switches on the pipelines of the refrigeration system. Failure of the sensor / switches, wiring harness, or control logic will not effectively protect the compressor. Furthermore, for refrigeration systems without low-pressure sensors, adding a sensor increases costs.

[0006] In other technical solutions, the system includes a device to prevent vacuum compression by the scroll compressor. This device leaks some of the refrigerant from the high-pressure side into the low-pressure chamber during vacuum compression. The disadvantage of this solution is that after the exhaust gas is introduced into the low-pressure chamber, this uncondensed refrigerant will re-enter the suction chamber and be compressed. Repeated compression may cause high temperatures, potentially damaging the compressor. Furthermore, if this device fails during compressor operation, the high and low-pressure chambers of the compressor will be directly connected when not under vacuum, resulting in repeated compression and increased exhaust temperature. Additionally, the compressor's operating status cannot be detected, and the position of valve components cannot be determined from outside the compressor, preventing inspectors / controllers from directly identifying any abnormalities in the refrigeration system or compressor.

[0007] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0008] To address the problems in the prior art, the present invention aims to provide a scroll compressor and a control method. The scroll compressor is equipped with a protection device that uses the pressure difference between the compression chamber and the suction chamber to control the position of the magnetic unit. The position of the magnetic unit is determined by the state of the sensing unit. The operating state of the compressor is judged by combining the state of the sensing unit and the state of the compressor. Based on this, the operating parameters of the compressor are controlled, such as stopping the compressor when the suction pressure is too low, to prevent failure.

[0009] A first aspect of the present invention provides a scroll compressor, comprising a stationary scroll, a moving scroll, an induction unit, and a magnetic unit including a magnetic valve body, wherein the stationary scroll and the moving scroll cooperate to form a compression chamber for compressing gas.

[0010] The two ends of the magnetic unit are respectively connected to the compression chamber and the intake chamber of the scroll compressor;

[0011] The magnetic unit is arranged opposite to the sensing unit. When the pressure difference between the compression chamber and the suction chamber meets the threshold condition, the magnetic valve body is within the sensing range of the sensing unit, and the sensing unit is in the first state.

[0012] When the pressure difference between the compression chamber and the intake chamber does not meet the threshold condition, the magnetic valve body is outside the sensing range of the sensing unit, and the sensing unit is in the second state.

[0013] According to a first aspect of the invention, the sensing unit includes a sensing switch and a signal wire electrically connected to the sensing switch, wherein the sensing switch is a reed switch or a reed switch.

[0014] When the signal wire is turned on, the sensing unit is in the first state;

[0015] When the signal wire is disconnected, the sensing unit is in the second state.

[0016] According to a first aspect of the invention, a channel is provided between the compression chamber and the intake chamber of the scroll compressor;

[0017] The magnetic unit also includes a movable component at one end that can reciprocate.

[0018] The magnetic valve body is disposed in the channel and connected to the reciprocating end of the movable component. The difference between the pressure of the compression chamber on one end face of the magnetic valve body and the pressure of the suction chamber on the other end face of the magnetic valve body controls the position of the magnetic valve body in the channel.

[0019] According to a first aspect of the invention, the axis of the channel is perpendicular to the axis of the compressor housing.

[0020] According to a first aspect of the invention, the movable component includes an elastic element, one end of which is fixed to the channel and the other end of which is a reciprocating movable end.

[0021] According to a first aspect of the invention, the elastic element is a reciprocating spring, and the movable component further includes a support rod disposed inside the reciprocating spring at the fixed end.

[0022] According to a first aspect of the invention, the side of the channel near the rotating shaft of the compressor is in communication with the compression chamber, and the side of the channel near the housing of the compressor is in communication with the intake chamber of the scroll compressor.

[0023] According to a first aspect of the invention, the stationary scroll disk includes a stationary disk and linear scroll teeth disposed on the stationary disk toward the moving scroll disk;

[0024] The channel is located on the static disk.

[0025] According to a first aspect of the invention, the Curie temperature of the material of the magnetic valve body is lower than a set value T. m .

[0026] According to a first aspect of the invention, the compressor further includes a control system, the control system comprising a monitoring module and a control module;

[0027] The monitoring module is used to monitor the status of the compressor and the status of the sensing unit;

[0028] The control module is used to generate control commands and control the compressor operating parameters based on the monitored state of the compressor and the state of the sensing unit, as well as preset logic.

[0029] According to a first aspect of the invention, the control system further includes an alert module for sending alert information to the user.

[0030] A second aspect of the present invention also provides a control method applicable to the scroll compressor, comprising the following steps:

[0031] S10: Monitor the operating status of the compressor and the status of the sensing unit;

[0032] S20: Based on the monitored operating status of the compressor and the status of the sensing unit, as well as the preset logic, generate control commands and control the compressor operating parameters.

[0033] According to a second aspect of the present invention, step S20 includes the following steps:

[0034] S21: Determine the compressor status;

[0035] If the compressor is running and operating at the first speed, then S22: Determine the state of the sensing unit;

[0036] If the sensing unit is in the second state and the time in the second state is greater than or equal to the first time threshold, then S23: control the compressor speed to the second speed, and the second speed is less than the first speed.

[0037] According to a second aspect of the invention, step S23 is followed by:

[0038] If the sensing unit is in the first state and the time in the first state is greater than or equal to the second time threshold, then S251: control the compressor speed to the first speed;

[0039] and / or

[0040] If the sensing unit is in the second state and the time in the second state is greater than or equal to the third time threshold, then S252: Control the compressor to stop running.

[0041] According to a second aspect of the invention, the monitoring module is further configured to monitor the number of times the control module controls the compressor to stop operating;

[0042] The control module is also used to start or stop the compressor's lock-up function;

[0043] When the number of times the control module stops the compressor exceeds a threshold, then S253: the control module activates the compressor's lock-up function.

[0044] According to a second aspect of the invention, the control module is further configured to activate or deactivate the compressor's lock-up function, and the method further includes the following steps:

[0045] If the compressor is in a stopped state and the sensing unit is in the first state, then S29: activate the compressor's lock-up function.

[0046] According to a second aspect of the present invention, the control system is further provided with a function to shield the monitoring of the state of the sensing unit; the method further includes the following steps:

[0047] If the compressor is in a powered-off state and the control module determines that the sensing unit is in the first state, the control system sends a command to the monitoring module to stop monitoring the status of the sensing unit.

[0048] When the scroll compressor of the present invention is running, the pressure difference between its suction chamber and compression chamber controls the position of the magnetic unit of the magnetic valve body. The position of the magnetic unit is determined by the state of the sensing unit. The operating state of the compressor is judged by combining the state of the sensing unit and the state of the compressor. Based on this, the operating parameters of the compressor are controlled to prevent failure. Attached Figure Description

[0049] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without inventive effort. Furthermore, the drawings are merely illustrative diagrams of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore, repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0050] Figure 1 This is a partial structural schematic diagram of a scroll compressor according to an embodiment of the present invention;

[0051] Figures 2 to 10 This is a force diagram of the magnetic valve body of a magnetic unit according to an embodiment of the present invention;

[0052] Figure 11 This is a block diagram of a scroll compressor control system according to an embodiment of the present invention;

[0053] Figure 12 This is a flowchart of a scroll compressor control method according to an embodiment of the present invention;

[0054] Figure 13 This is a logic diagram of a scroll compressor control method according to an embodiment of the present invention. Detailed Implementation

[0055] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0056] In this specification, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics represented in connection with that embodiment or example, which are included in at least one embodiment or example of this specification. Furthermore, the specific features, structures, materials, or characteristics represented may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples represented in this specification, as well as the features of different embodiments or examples.

[0057] Throughout this specification, when it is said that a device is "connected" to another device, this includes not only "direct connection" but also "indirect connection" by placing other components in between. Terms indicating relative space, such as "below" and "above," are used to more easily explain the relationship of one device relative to another illustrated in the figures. These terms refer not only to their meaning in the figures but also to other meanings or operations of the device in use. For example, if the device in the figures is rotated, a device previously described as "below" another device may now be described as "above" another device. Therefore, the exemplary term "below" encompasses both above and below. The device may be rotated 90° or other angles, and the terms representing relative space are interpreted accordingly.

[0058] Although the terms first, second, etc., are used in some instances herein to refer to various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, first interface and second interface, etc., are used. Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, step, operation, element, component, item, kind, and / or group, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition will only occur if the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0059] Although not explicitly defined, all terms, including technical and scientific terms used herein, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this specification pertains. Terms defined in commonly used dictionaries shall be further interpreted as having a meaning consistent with relevant technical literature and the content of this present instruction, and shall not be over-interpreted as having an ideal or overly formulaic meaning unless otherwise defined.

[0060] This invention provides a scroll compressor and its control method. The compressor includes a stationary scroll, a moving scroll, a sensing unit, and a magnetic unit including a magnetic valve body. The stationary and moving scrolls cooperate to form a compression chamber for compressing gas. The two ends of the magnetic unit are respectively connected to the compression chamber and the suction chamber of the scroll compressor. The magnetic unit and the sensing unit are arranged opposite to each other. When the pressure difference between the compression chamber and the suction chamber meets a threshold condition, the magnetic valve body is within the sensing range of the sensing unit, and the sensing unit is in a first state. When the pressure difference between the compression chamber and the suction chamber does not meet the threshold condition, the magnetic valve body is outside the sensing range of the sensing unit, and the sensing unit is in a second state. The scroll compressor of this invention is equipped with a protection device. This protection device uses a mechanical device that utilizes the pressure difference between the compression chamber and the suction chamber. By sensing the position of the mechanical device through the sensing unit and combining the state of the sensing unit with the compressor's operating state, it is possible to determine whether the compressor is operating normally. Based on this, the compressor's operating parameters are controlled, such as stopping the compressor when the suction pressure is too low, to prevent failure.

[0061] The scroll compressor and control method of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments are not intended to limit the scope of protection of the present invention.

[0062] Figure 1 A partial structural diagram of a scroll compressor according to an embodiment of the present invention is shown. Specifically, the scroll compressor includes a stationary scroll 1, a moving scroll 2, an induction unit 3, and a magnetic unit 4 including a magnetic valve body 41, all housed in a compressor housing 9. The stationary scroll 1 and the moving scroll 2 mesh with each other to form a compression chamber for compressing gas. The stationary scroll 1 includes a stationary disk and linear scroll teeth disposed on the stationary disk facing the moving scroll. The moving scroll 2 includes a moving disk and linear scroll teeth disposed on the moving disk facing the stationary scroll. The two ends of the magnetic unit 4 are respectively connected to the compression chamber and the suction chamber of the scroll compressor. The suction chamber of the scroll compressor is the cavity between the compressor's compression mechanism and the compressor's rear housing.

[0063] The magnetic unit 4 is arranged opposite to the sensing unit 3. This "opposite arrangement" means that within the movable range of the magnetic valve body of the magnetic unit 4, there exists a position that can be sensed by the sensing unit 3, thereby changing the state of the sensing unit. When the pressure difference between the compression chamber and the suction chamber meets a threshold condition, the magnetic valve body is within the sensing range of the sensing unit 3, and the sensing unit is in a first state. When the pressure difference between the compression chamber and the suction chamber does not meet the threshold condition, the magnetic valve body is outside the sensing range of the sensing unit, and the sensing unit is in a second state. Of course, the scroll compressor also includes an exhaust port 8 and a pressure relief valve 7 disposed on the stationary scroll plate 1, an exhaust valve plate baffle 6 disposed on the housing, and fixing bolts for fixing the stationary scroll plate and the housing 9, etc., which will not be described in detail here.

[0064] In some embodiments, the sensing unit 4 includes a sensing switch and a signal wire electrically connected to the sensing switch. The sensing switch is a normally open or normally closed reed switch or a reed switch. When the signal wire is on, the sensing unit is in a first state; when the signal wire is off, the sensing unit is in a second state. The signal wire of the sensing element can be connected to the controller of the scroll compressor via terminals or embedded wires inside the housing, or via a channel machined inside the compressor housing and then connected to the compressor controller via contacts or wires. The connection method is not limited here. The controller determines the position of the magnetic valve body by detecting the state and on / off time of this signal wire. In practical use, the on state of the signal wire can be set, i.e., the sensing unit can sense the state of the magnetic valve when the compressor is operating normally, and the off state of the signal wire, i.e., the sensing unit cannot sense the state of the magnetic valve when the compressor is operating abnormally.

[0065] The magnetic unit and corresponding sensing unit of the present invention can be regarded as a protection device for a scroll compressor. The pressure difference between the compression chamber and the suction chamber controls the position of the magnetic valve body of the magnetic unit. The state of the sensing unit is determined according to the position of the magnetic valve body. By monitoring the state of the sensing unit, the pressure of the compression chamber and the suction chamber can be monitored.

[0066] A channel is provided between the compression chamber and the intake chamber of the scroll compressor. Figure 1 In this embodiment, the channel 11 is disposed on the stationary plate, and the magnetic unit may further include a movable component with one end capable of reciprocating movement; the magnetic valve body 41 is disposed on the channel 11 and connected to the reciprocating end of the movable component, and the difference between the pressure of the compression chamber on one end face of the magnetic valve body 41 and the pressure of the suction chamber on the other end face of the magnetic valve body controls the position of the magnetic valve body in the channel. The movable component includes an elastic element, one end of which is fixed to the channel, and the other end is a reciprocating end. The elastic element may be a reciprocating spring or other components. The movable component also includes a support rod, which is disposed inside the reciprocating spring at the fixed end, thereby improving the stability of the reciprocating motion of the elastic element. The channel 11 may be as follows: Figure 1 The structure includes a valve sleeve section for the operation of the magnetic valve body 41 and a pressure-feeding section connected to the compression chamber. According to a first aspect of the invention, the elastic element is a reciprocating spring.

[0067] In practice, scroll compressors can be horizontal or vertical, and the axis of the channel can be set perpendicular to the axis of the compressor housing 9. For example, if the scroll compressor is vertical, the channel 11 can be arranged as follows: Figure 1 Horizontal settings.

[0068] Whether the scroll compressor is horizontal or vertical depends slightly on the force applied to the magnetic valve body 41 of the magnetic unit. In the scroll compressor, low-temperature, low-pressure gas is compressed through several compression chambers formed by the stationary scroll 1 and the moving scroll 2, then transmitted to the central exhaust port 8 and discharged into the exhaust chamber via the exhaust valve baffle 6. During normal operation, the pressure ratio between the intake chamber and the central compression chamber is x, which is related to the position of the channel 11 and the structure of the stationary scroll 1 and the moving scroll 2. When the pressure in the intake chamber of the scroll compressor is too low, the pressure in the central compression chamber will also decrease.

[0069] One side of the magnetic valve body 41 is connected to the suction chamber, and the other side is connected to the compression chamber. That is, the gas pressure on one side is equal to the suction chamber pressure, and the gas pressure on the other side is equal to the compression chamber pressure. The position where channel 11 connects to the compression chamber can be determined according to the specific structure of the scroll compressor. It can be set at a position where the pressure in the compression chamber is ε times the suction chamber pressure during the operation of the moving and stationary discs. After the compressor runs stably, the gas pressure in the compression chamber at this position has a relatively stable pressure ratio / pressure difference with the pressure in the suction chamber. This pressure difference can be calculated using the following formula:

[0070] ΔP=(ε-1)·P s ;

[0071] Among them, P s This represents the gas pressure in the intake chamber. If only the thrust difference between the gases on both sides of the magnetic valve body 41 is considered, it can be calculated using the following formula:

[0072] ΔF=(ε-1)·P s ·A, where A is the cross-sectional area of ​​the channel at the magnetic valve body 41.

[0073] It can be seen that when the air pressure P in the inspiratory chamber s If the pressure difference is too small, the thrust difference ΔF will also be very small. When the compressor operates under vacuum in the suction chamber, then P... s As the thrust difference ΔF approaches zero, the thrust difference also approaches zero.

[0074] The elastic force exerted by the elastic element connected to the magnetic valve body 41 on the magnetic valve body 41 can be calculated by the following formula:

[0075] F k =k*x;

[0076] Where k is the elastic coefficient of the elastic element, and x is the displacement of the moving end of the elastic element relative to the state when it is not under force.

[0077] When the scroll compressor is operating under normal conditions, i.e., in a non-vacuum state, if the pressure in the suction chamber is higher than a certain specification value, then the pressure in the compression chamber will be ε times the specification value. The sum of the elastic force on the magnetic valve body 41, the gas thrust at the suction chamber end, and gravity (if the magnetic valve body 41 is not horizontally arranged) is less than the gas thrust at the compression chamber end. Therefore, the magnetic valve body 41 will overcome the elastic force and gravity (if the magnetic valve body 41 is not horizontally arranged) and move towards the sensing range of the sensing unit 3. At this time, the state of the sensing unit 3 is affected by the magnetic valve body 45, and the electrical signal is transmitted to the compressor controller through the signal wire. The movement of the magnetic valve body 41 at this time is illustrated as follows: Figures 2 to 4 As shown, where,

[0078] Figure 2 The magnetic valve body 41 is horizontally set, with F k +P s ·A<P mid·A;P mid This refers to the gas pressure in the compression chamber;

[0079] Figure 3 The magnetic valve body 41 is vertically arranged, and the sensing range of the sensing unit is at the upper end, with F k +P s ·A+G<P mid A;

[0080] Figure 3 The magnetic valve body 41 is vertically arranged, and the sensing range of the sensing unit is at the lower end, with F k +P s ·A<P mid ·A+G.

[0081] When a scroll compressor is operating under vacuum, because no gas flows into the compressor's suction port, both the suction chamber and the intermediate compression chamber are close to a vacuum. The gas is concentrated in the chamber at the center of the scroll plate, so there is no pressure difference between the suction chamber and the intermediate compression chamber, and the valve body remains in the same position as when the compressor is stopped. The diagram illustrates the movement of the valve body at this time. Figures 5 to 7 As shown: Among them,

[0082] Figure 5 The magnetic valve body 41 is horizontally set, with F k +P s ·A>P mid • A+G;

[0083] Figure 6 The magnetic valve body 41 is vertically arranged, and the sensing range of the sensing unit is at the upper end, with F k +P s ·A+G>P mid A;

[0084] Figure 7 The magnetic valve body 41 is vertically arranged, and the sensing range of the sensing unit is at the lower end, with F k +P s ·A>P mid ·A+G.

[0085] As can be seen from the above discussion, once the elastic coefficient of the elastic element, the cross-sectional area of ​​the magnetic valve or channel, and the channel structure are determined, the pressure difference between the compression chamber and the suction chamber determines the position of the magnetic valve body. When the air pressure P in the suction chamber of the scroll compressor... s When the value falls below the specified value, the thrust difference between the two sides of the magnetic valve body 41 decreases, and the magnetic valve body 41 cannot move into the sensing range of the sensing unit. (The diagram illustrates the movement of the magnetic valve body 41 at this time.) Figures 8 to 10 As shown, where,

[0086] Figure 5 The magnetic valve body 41 is horizontally set, with Fk' +P s ·A>P mid ·A+G;F k' This represents the elastic force corresponding to the minimum displacement of the magnetic valve body 41 as it moves from the bottom to the sensing range of the sensing unit;

[0087] Figure 6 The magnetic valve body 41 is vertically arranged, and the sensing range of the sensing unit is at the upper end, with F k' +P s ·A+G>P mid A;

[0088] Figure 7 The magnetic valve body 41 is vertically arranged, and the sensing range of the sensing unit is at the lower end, with F k' +P s ·A>P mid ·A+G.

[0089] In summary, by selecting appropriate parameters, when the compressor suction chamber pressure is higher than a certain specification value P0, the magnetic valve body 41 moves to the sensing range of the sensing unit 3, at which point P... mid =εP0. These parameters satisfy the following conditions:

[0090] When the magnetic valve body 41 is set horizontally: F k +P0·A=P mid ·A

[0091] When the magnetic valve body 41 is vertically positioned and the sensing range of the sensing unit is at the upper end: F k +G+P0·A=P mid A;

[0092] When the magnetic valve body 41 is vertically positioned, the sensing range of the sensing unit is at the lower end: F k +P0·A=P mid ·A+G.

[0093] Preferably, the magnetic valve body 41 is vertically arranged and the sensing range of the sensing unit is at the upper end. In this case, there is no need to set a reset elastic element.

[0094] Meanwhile, there is a certain relationship between the magnetic valve body and the exhaust temperature. After testing and calibration, the magnetic valve body can be selected from materials with a Curie temperature lower than a preset value T. m The magnetic valve body, at this time, when the compressor discharge temperature is too high, such as the temperature of the magnetic valve body > T m When the magnetic valve body loses its magnetism, the sensing unit no longer detects it and enters the second state. The compressor controller detects that the signal wire is disconnected and considers the compressor to be in an abnormal operating state. This setting helps prevent excessively high exhaust temperatures and protects the compressor's compression mechanism and refrigerant oil. Preset value Tm It can be determined based on the position of the magnetic valve body and the temperature difference with the actual exhaust temperature after calibration.

[0095] To facilitate monitoring of the protection devices of the scroll compressor, in some embodiments, the scroll compressor may include a control system. Figure 11 This is a block diagram of a scroll compressor control system according to an embodiment of the present invention. The control system includes a monitoring module M100 and a control module M200.

[0096] The monitoring module M100 is used to monitor the status of the compressor and the status of the sensing unit;

[0097] The control module M200 is used to generate control commands and control the compressor operating parameters based on the monitored state of the compressor and the state of the sensing unit, as well as preset logic.

[0098] In some other embodiments, the control system may also include an alert module M300 for sending alert information to the user.

[0099] The scroll compressor of this invention utilizes a pressure difference of a fixed ratio between the compression chamber and the suction chamber, and sets up a mechanical device (magnetic unit) to control this pressure difference. A sensing unit detects the position of this mechanical device to determine whether the compressor is operating within the normal range. If the pressure difference is too small, it indicates that the compressor's suction pressure is too low, and operation should be stopped to prevent failure.

[0100] The present invention also provides a scroll compressor control method, which is applicable to the scroll compressor, see [link to relevant documentation]. Figure 12 Flowcharts and Figure 13 The logic diagram, specifically, the control method includes the following steps:

[0101] S10: Monitoring module M100 monitors the compressor's operating status and the status of the sensing unit;

[0102] S20: The control module M200 generates control commands and controls the compressor's operating parameters based on the monitored compressor's operating status, the status of the sensing unit, and preset logic.

[0103] More specifically, step S20 may include the following steps:

[0104] S21: Control module M200 determines the compressor status;

[0105] If the compressor is running and operating at the first speed, then S22: Determine the state of the sensing unit; the first speed here can be the state where the compressor is started and operating at the first power, which can be the most economical or most commonly used operating state of the compressor.

[0106] If the sensing unit is in the second state and the time spent in the second state is greater than or equal to the first time threshold, then S23: the compressor speed is controlled to a second speed, and the second speed is less than the first speed. It should be noted that the control method described here is based on... Figure 1 Taking the magnetic valve component structure as an example, in this embodiment, the pressure in the middle compression chamber and the pressure in the suction chamber are greater than a predetermined difference, that is, when the pressure difference between the compression chamber and the suction chamber meets the threshold condition, the compressor is in normal operation. At this time, F k +P s ·A<P mid • A, the elastic element is in a compressed state, the magnetic valve is within the sensing range of the sensing unit, and the sensing unit is in the first state, meaning the compressor controller detects that the sensing unit is in the first state, indicating that the compressor is operating normally. The compressor is in normal operation when the pressure difference between the compression chamber and the suction chamber is not greater than a predetermined value, i.e., the pressure difference between the compression chamber and the suction chamber does not meet the threshold condition. At this time, F... k +P s ·A≥P mid • In scenario A, the elastic element is in an extended state, and the magnetic valve moves out of the sensing range of the sensing unit. The sensing unit is in a second state, meaning the compressor controller detects that the sensing unit is in the second state, indicating that the compressor is operating in an abnormal state. Alternatively, in other embodiments, the magnetic valve can be positioned within the sensing range of the sensing unit. The first state corresponds to an abnormal pressure difference between the compression chamber and the suction chamber, indicating an abnormal compressor state. Conversely, the magnetic valve can be positioned outside the sensing range, and the second state corresponds to a normal pressure difference between the compression chamber and the suction chamber, indicating a normal compressor state. Further details will not be elaborated here.

[0107] If the sensing unit is in the first state for a certain period of time, then S221: The controller controls the compressor to run at the first speed. Steps S21 to S221 and S21 to S23 can be seen as follows: After the compressor starts from the unstarted state (State0), the compressor controller detects that after a certain period of time (T0) after the compressor starts, the sensing unit is in the first state for a certain period of time. The controller then determines that the air pressure in the compressor's suction chamber is normal, and the compressor runs in State1. If the compressor controller detects that after a certain period of time (T0) after the compressor starts, the sensing unit is in the second state for a certain period of time (T1), the controller determines that the air pressure in the compressor's suction chamber is abnormal. At this time, the compressor speed needs to be reduced at a certain rate to control the compressor speed to the second speed, which is less than the first speed, to prevent failure caused by high-speed friction. The compressor state is State2. In some control systems, a warning module is also included. In some embodiments, the warning module can send a warning message (Warning1) to the user, such as displaying a warning message on the display panel or displaying the current compressor status.

[0108] Furthermore, after step S23, the control method may further include the following steps:

[0109] S24: Determine the state of the sensing unit;

[0110] If the sensing unit is in the first state and the time in the first state is greater than or equal to the second time threshold, then S251: control the compressor speed to the first speed; that is, after the compressor is in State2, if the controller detects that the sensing unit has returned to the first state and lasts for a certain time T2, then the controller restores the compressor speed at a certain acceleration rate, and after the operating speed is restored, the compressor state returns to the normal state State1.

[0111] In some embodiments, if the sensing unit is in the second state and the time in the second state is greater than or equal to a third time threshold, then S252: control the compressor to stop running, that is, if the compressor is in State 2 and lasts for a certain period of time T3 (the sensing unit does not return to the first state within T3 time), then the compressor needs to be turned off, and the compressor is in State 3. Of course, in embodiments where the control system also includes a warning module, the warning module can report fault state State 3 and fault code ErrorCode 1, etc.

[0112] Furthermore, the monitoring module is also used to monitor the number of times the control module stops the compressor; that is, the monitoring module can monitor the number of times step S252 occurs within a certain period of time. The control module is also used to start or stop the compressor's lock-up function; when the number of times the control module stops the compressor exceeds a threshold, then S253: the control module starts the compressor's lock-up function. In this embodiment, when the compressor is in State2 for a certain period of time T3 more than a certain number of times within a certain period of time, that is, when the compressor refrigeration system has a low-pressure fault that occurs and repeats multiple times, the compressor's lock-up function can be started to prevent accidental restart of the compressor.

[0113] Of course, after the compressor is completely shut down and the compressor fault is confirmed to be eliminated, or after a certain time T4 after the compressor is completely shut down (i.e., the fault is reset according to time T4), the compressor returns to State 0 and can respond to the target speed.

[0114] In practical use, the control module is also used to activate or deactivate the compressor's lock-up function. The method further includes the following steps: If the compressor is in a stopped but energized state, and the control module determines that the sensing unit is in the first state, then S29: The controller activates the compressor's lock-up function. The above steps mean that when the compressor is not running, the magnetic valve body is subjected to force. At this time, it is considered that the magnetic unit or sensing unit has failed, thereby activating the compressor's lock-up function to prevent accidental compressor startup. In practical use, the control system also has a function to shield the monitoring of the sensing unit's status, i.e., it has a shielding protection device function. When the compressor is in a stopped but energized state, and the control module determines that the sensing unit is in the first state, it is considered that the magnetic unit or sensing unit has failed. The control system sends a command to the monitoring module to stop monitoring the sensing unit's status, i.e., step S10 is no longer executed. This process employs a strategy of shielding the failure protection device, thus ensuring that it does not affect the normal operation of the compressor.

[0115] The control method of the present invention can detect whether the suction chamber pressure of the scroll compressor is too low, and execute a speed reduction or shutdown command through the compressor controller according to certain logic judgment, so that the compressor scroll plate does not generate high temperature due to high compression ratio and oil shortage friction, thus protecting the compression unit.

[0116] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention and should not be construed as limiting the specific implementation of the invention to these descriptions. It will be apparent to those skilled in the art that this application is not limited to the details of the above exemplary embodiments, and that the application can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be embraced within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A scroll compressor, characterized in that, It includes a stationary volute, a moving volute, a sensing unit, and a magnetic unit including a magnetic valve body. The stationary volute and the moving volute cooperate to form a compression chamber for compressing gas. The two ends of the magnetic unit are respectively connected to the compression chamber and the intake chamber of the scroll compressor; The magnetic unit is arranged opposite to the sensing unit. When the pressure difference between the compression chamber and the suction chamber meets the threshold condition, the magnetic valve body is within the sensing range of the sensing unit, and the sensing unit is in the first state. When the pressure difference between the compression chamber and the suction chamber does not meet the threshold condition, the magnetic valve body is located outside the sensing range of the sensing unit, and the sensing unit is in the second state. The Curie temperature of the material of the magnetic valve body is lower than the set value T. m ; When the temperature of the magnetic valve body > T m When the magnetic valve body loses its magnetism, the sensing unit can no longer sense the magnetic valve body and is in the second state.

2. The scroll compressor according to claim 1, characterized in that, The sensing unit includes a sensing switch and a signal wire electrically connected to the sensing switch. The sensing switch is a magnetic reed switch or a sensing reed switch. When the signal wire is turned on, the sensing unit is in the first state; When the signal wire is disconnected, the sensing unit is in the second state.

3. The scroll compressor according to claim 1, characterized in that, A channel is provided between the compression chamber and the intake chamber of the scroll compressor; The magnetic unit also includes a movable component at one end that can reciprocate. The magnetic valve body is disposed in the channel and connected to the reciprocating end of the movable component. The difference between the pressure of the compression chamber on one end face of the magnetic valve body and the pressure of the suction chamber on the other end face of the magnetic valve body controls the position of the magnetic valve body in the channel.

4. The scroll compressor according to claim 3, characterized in that, The axis of the channel is perpendicular to the axis of the compressor housing.

5. The scroll compressor according to claim 3, characterized in that, The movable component includes an elastic element, one end of which is fixed to the channel, and the other end is a reciprocating movable end.

6. The scroll compressor according to claim 5, characterized in that, The elastic element is a reciprocating spring, and the movable component also includes a support rod, which is disposed inside the reciprocating spring at the fixed end.

7. The scroll compressor according to claim 3, characterized in that, The side of the channel near the rotating shaft of the compressor is connected to the compression chamber, and the side of the channel near the housing of the compressor is connected to the intake chamber of the scroll compressor.

8. The scroll compressor according to claim 3, characterized in that, The stationary volute includes a stationary disk and linear volute teeth disposed on the stationary disk facing the moving volute. The channel is located on the static disk.

9. The scroll compressor according to claim 1, characterized in that, The compressor also includes a control system, which includes a monitoring module and a control module. The monitoring module is used to monitor the status of the compressor and the status of the sensing unit; The control module is used to generate control commands and control the compressor operating parameters based on the monitored state of the compressor and the state of the sensing unit, as well as preset logic.

10. The scroll compressor according to claim 9, characterized in that, The control system also includes an alert module for sending alert messages to users.

11. A control method applicable to the scroll compressor of claim 9, characterized in that, Includes the following steps: S10: Monitor the operating status of the compressor and the status of the sensing unit; S20: Based on the monitored operating status of the compressor and the status of the sensing unit, as well as the preset logic, generate control commands and control the compressor operating parameters.

12. The control method according to claim 11, characterized in that, Step S20 includes the following steps: S21: Determine the compressor status; If the compressor is running and operating at the first speed, then S22: Determine the state of the sensing unit; If the sensing unit is in the second state and the time in the second state is greater than or equal to the first time threshold, then S23: control the compressor speed to the second speed, and the second speed is less than the first speed.

13. The control method according to claim 12, characterized in that, The process following step S23 also includes: S24: Determine the state of the sensing unit; If the sensing unit is in the first state and the time in the first state is greater than or equal to the second time threshold, then S251: control the compressor speed to the first speed; and / or If the sensing unit is in the second state and the time in the second state is greater than or equal to the third time threshold, then S252: Control the compressor to stop running.

14. The control method according to claim 13, characterized in that, The monitoring module is also used to monitor the number of times the control module stops the compressor. The control module is also used to start or stop the compressor's lock-up function; When the number of times the control module stops the compressor exceeds a threshold, then S253: the control module activates the compressor's lock-up function.

15. The control method according to claim 12, characterized in that, The control module is also used to activate or deactivate the compressor's lock-up function, and the method further includes the following steps: If the compressor is in a stopped state and the sensing unit is in the first state, then S29: activate the compressor's lock-up function.

16. The control method according to claim 11, characterized in that, The control system is also equipped with a function to shield the monitoring of the state of the sensing unit; the method further includes the following steps: If the compressor is in a powered-off state and the control module determines that the sensing unit is in the first state, the control system sends a command to the monitoring module to stop monitoring the status of the sensing unit.

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