Method for controlling a scroll compressor and control device for a scroll compressor

Abstract

The present invention relates to a method for controlling a scroll compressor, particularly a scroll compressor having first and second spirals arranged nested together, where the first spiral is movable relative to the second spiral to drive the scroll compressor for decompression or compression. To enable a longer operating life of the scroll compressor, the method includes the steps of: driving a motor to drive the first spiral; measuring multiple acceleration forces acting on the scroll compressor, where the acceleration forces depend on the relative position and / or position angle of the first spiral with respect to the second spiral; and driving the motor such that the acceleration forces are reduced by adapting the torque curve of the motor according to the measured acceleration forces.

Description

Technical Field

[0001] The present invention relates to a method for controlling a scroll compressor and a control device for a scroll compressor.

Background Art

[0002] A scroll compressor is a machine that can further transfer and additionally compress a gas, generally a fluid, in a manner similar to a pump. For this purpose, a scroll compressor has two spirals arranged concentrically with each other, and as they move in opposite directions to each other, the gas is compressed little by little. For this purpose, for example, the first spiral is fixedly positioned, and the second spiral is movable around the center point of the first spiral on a circular orbit without particular self-rotation. By the second spiral moving relative to the first spiral, a chamber or a hollow chamber is always formed between the two spirals, and it is displaced toward the center point of the spiral or outward according to the rotational direction of the movement. Usually, the spirals are moved such that the gas to be pumped is sucked in from the outside, compressed inside the pump, and discharged through the connection end at the center of the spiral.

[0003] A scroll compressor may generate an accelerating force due to a compression or decompression process, and in particular based on the fact that the torque required over a circular orbit is not constant, and this force is particularly transferred to the scroll housing. As a result, strong vibrations may occur, which may damage the spirals and / or its housing of the scroll compressor over a long period of time, thus reducing the driving life of the scroll compressor.

[0004] Furthermore, in a vehicle driven electrically (without an internal combustion engine), the scroll compressor or scroll compressor must operate with as little vibration as possible. This is because vibrations in an electric vehicle are fundamentally less than those in a vehicle driven by fossil fuel, and an additional source of vibration, such as a scroll compressor, is not desirable.

Summary of the Invention

Problems to be Solved by the Invention

[0005] In view of this, a method for substantially extending the driving life of a scroll compressor is required.

Means for Solving the Problems

[0006] According to the present invention, for this purpose, a method for controlling the scroll compressor according to claim 1 is provided. This method is used for controlling a scroll compressor having first and second spirals arranged in particular in a nested manner. In that case, the first spiral is movable relative to the second spiral for the decompression drive or compression drive of the scroll compressor. The method has the following steps: - Driving a motor to move the first spiral; - Measuring a number of accelerating forces applied to the scroll compressor, where the accelerating force depends on the relative position and / or angular position of the first spiral with respect to the second spiral; - Driving the motor so that the accelerating force is reduced by adapting the torque transition of the motor according to the measured accelerating force.

[0007] This method has the advantage that it can better control a scroll compressor without an internal or built-in sensor. Thereby, it is not necessary to replace the already known electrically driven scroll compressor with a newly conceived and configured scroll compressor, thereby saving the cost and time for upgrading the scroll compressor as appropriate.

[0008] By driving with less vibration, the components of the scroll compressor, especially the spiral and the members coupled thereto, are handled carefully and protected from excessive wear. At the same time, a longer driving life of the scroll compressor can be guaranteed accordingly.

[0009] The accelerating force is preferably measured by a suitable sensor, and the sensor can be arranged outside the scroll compressor. In addition, the scroll compressor can be defined and measured with respect to its suction pressure and / or its high pressure. The additional information provided is the torque transition or characteristic curve diagram of the scroll compressor and the electric motor, which describes the required or provided torque according to the angle / phase and / or the rotational speed.

[0010] Furthermore, it has been revealed that it is preferable if the adaptation of the motor torque transition has the following steps: - Shift the torque phase of the motor in the first direction; - Measure a number of accelerating forces; If the accelerating force increases, shift the torque phase of the motor in the second direction opposite to the first direction; If the accelerating force decreases, further shift the torque phase of the motor in the current direction until the minimum of the accelerating force is achieved.

[0011] These steps have the advantage that the output to be provided by the motor does not change and thus no additional electrical output is required. Also, to reduce vibrations, the motor can be maintained and does not need to be replaced with a more powerful motor. The shift in torque to be provided by the motor is effected in accordance with the angle / phase or position of the second spiral relative to the first spiral. Each electric motor has a characteristic curve which describes the torque of the motor in accordance with the current and / or voltage provided and the angle of the motor shaft. As soon as the torque of the motor is phase-shifted or angle-shifted so as to substantially overlap equally with the required torque characteristic curve of the scroll compressor, the difference between the torque provided by the motor and the torque required by the scroll compressor decreases. In that case, vibrations occur only when the required torque becomes greater in amplitude than the torque provided. The characteristic curve of the torque required for the scroll compressor is periodically repeated after 360°, thus after one revolution of the spiral, and has only one maximum, so it is immediately recognizable by what direction, in particular clockwise or counterclockwise, the angle shift / phase shift of the torque of the electric motor must be made in order to reduce the vibrations and for that purpose.

[0012] Similarly, the adaptation of the torque progression of the motor preferably additionally or alternatively has the following steps: - vary the torque amplitude of the motor in a first direction; - measure a number of accelerating forces; when the accelerating force increases, vary the torque amplitude of the motor in a second direction opposite to the first direction; when the accelerating force decreases, further vary the torque amplitude of the motor in the then direction until the minimum of the accelerating force is achieved.

[0013] These preferred steps can be used, additionally or alternatively, to shift the torque phase. In that case, the strength or amplitude of the torque is varied until the vibration reaches a minimum and / or the change in vibration, in particular its decrease, no longer exceeds a predefined / predetermined value. Similarly, the amplitude of the torque can be decreased until the vibration starts to increase again. These steps have the advantage of providing an amount of energy adapted to the requirements of the scroll compressor and at the same time enabling a vibration-free and energy-efficient drive.

[0014] When the accelerating force decreases or at that time, preferably the torque amplitude of the motor is further varied in the direction at that time until the decreasing change in the accelerating force reaches a predefined value. This step accelerates the method and terminates it in a predictable period. Even when the motor provides a torque amplitude exceeding the value required by the scroll compressor, the vibration can still be measured. Despite the change in torque amplitude, as soon as the change in vibration no longer decreases, the output enhancement of the motor does not increase infinitely but is stopped; thereby saving electrical energy in particular.

[0015] In another preferred embodiment, the accelerating force is decreased such that, namely, the measured maximum value and / or the sum of the measured values is decreased over at least one revolution or a revolution section of the first or second spiral. This step ensures that the vibration is decreased not only between one point in time and / or one angular position but preferably over one or more complete rotations / revolutions of the movable spiral.

[0016] According to the present invention, similarly, a control device as described in claim 4 is provided. This control device is designed for a scroll compressor having first and second spirals arranged concentrically. Furthermore, the control device is as follows: - Control the motor to move the first spiral relative to the second spiral for decompression drive or compression drive of the scroll compressor; - Detect a number of accelerating forces applied to the scroll compressor as measured values, where the accelerating forces depend on the relative position and / or angular position of the first spiral relative to the second spiral; and - Control the motor so that the detected measured value of the accelerating force is reduced by adapting the torque transition of the motor according to the measured accelerating force. It is designed as follows.

[0017] The control device according to the present invention has the same advantages as the above-described control method, and is formed to substantially perform the same steps as this method, particularly additionally or alternatively, or to be implemented in a scroll compressor. Conversely, the method according to the present invention can additionally or alternatively have the features of the control device according to the present invention, particularly its control steps.

[0018] Furthermore, the control device preferably adapts the torque transition of the motor as follows: that is, the torque phase of the motor is shifted in a first direction; in that case, when the detected measured value of the accelerating force increases, the torque phase of the motor is shifted in a second direction opposite to the first direction, and when the detected measured value of the accelerating force decreases, the torque phase of the motor is further shifted in the direction at that time until the minimum of the accelerating force is achieved.

[0019] Preferably, the control device adapts the torque transition of the motor as follows: that is, the torque amplitude of the motor is shifted in a first direction; in that case, when the detected measured value of the accelerating force increases, the torque amplitude of the motor is shifted in a second direction opposite to the first direction, and when the detected measured value of the accelerating force decreases, the torque amplitude of the motor is further shifted in the direction at that time until the minimum of the accelerating force is achieved.

[0020] In another preferred embodiment, the control device is designed such that, when the accelerating force decreases, the torque amplitude of the motor is changed in the direction at that time until the decreasing change in the accelerating force reaches a predetermined value.

[0021] Similarly, it has been clarified that it is preferable if the control device is designed to reduce the accelerating force such that the measured maximum value and / or the sum of the measured values is reduced over at least one revolution or a section of a revolution of the first spiral.

[0022] Furthermore, a scroll compressor having the control device according to the present invention is provided, and a computer-readable memory medium having stored instructions is provided, and the instructions, when implemented by at least one processor, cause the at least one processor to implement the method according to the present invention.

[0023] The method described below relates substantially to preferred embodiments of the control device according to the present invention and the method according to the present invention, and in that case these figures are not used to limit the present invention but are used substantially for explanation.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5a

Figure 5b

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0025] Figure 1 shows a torque characteristic curve diagram for a scroll compressor having an inlet pressure of 3 / 20; i.e., 3 bar and an outlet pressure of 20 bar. To achieve the pressure ratio described above, the torque that is on average required for the scroll compressor is approximately 3.2 Nm (see the dashed line). The actual torque (see the solid line) starts at approximately 2.8 Nm at 0 degrees and continuously decreases to a minimum of approximately 2.4 Nm at 60 degrees according to the orbiting angle. Next, the required torque continuously increases to a maximum of approximately 4.5 Nm at 200 degrees and continuously decreases to approximately 2.8 Nm at 360 degrees. This characteristic curve is repeated for each orbiting path.

[0026] Figure 2 shows a torque characteristic curve diagram for a scroll compressor having an inlet and outlet pressure ratio of 3 / 25. To achieve the pressure ratio described above, the torque that is on average required for the scroll compressor is approximately 3.6 Nm (see the dashed line). The actual torque starts at approximately 3.4 Nm at 0 degrees (see the solid line) and continuously decreases to a minimum of approximately 2.5 Nm at 70 degrees according to the orbiting angle. Next, the required torque continuously increases to a maximum of approximately 5.3 Nm at approximately 230 degrees and continuously decreases to approximately 3.4 Nm at 360 degrees. As in Figure 1, this characteristic curve is repeated for each orbiting path.

[0027] Figure 3 shows a torque characteristic curve diagram for a scroll compressor having an inlet and outlet pressure ratio of 4 / 15. To achieve the pressure ratio described above, the torque required for the scroll compressor is approximately 3.0 Nm (see the dashed line). According to the orbiting angle, the actually required torque (see the solid line) starts at approximately 2.6 Nm at 0 degrees and continuously increases to a maximum of approximately 3.7 Nm at 110 degrees. Next, the required torque continuously decreases to a minimum of approximately 2.6 Nm at approximately 360 degrees. As in Figure 1, this characteristic curve is repeated for each orbiting path.

[0028] Figure 4 shows the shaft rotation speed diagram of a scroll compressor at a pressure ratio of 3 / 20. The average rotation speed is 1500 revolutions per minute (abbreviation: rpm). As shown in Figures 1 to 3, since the required torque is different, the acceleration or deceleration of the shaft rotation or the movable spiral is performed according to the circumferential orbit angle, or according to whether the required torque is above or below the average value of the scroll compressor.

[0029] Figure 5A shows a side view of the housing of a scroll compressor, and the housing has fixing point mounts 1 and 2 for fixing the housing, for example, inside a vehicle.

[0030] Figure 5B shows the acceleration force diagram applied to the fixing point mounts 1 and 2 of the scroll compressor in Figure 5A. Due to the vibration of the scroll compressor, the acceleration force acts on the fixing point and can be measured by an appropriate sensor. The characteristic curve of the acceleration force at mount 1 is mirror-inverted or inverted about the X-axis with respect to the characteristic curve of mount 2.

[0031] Figure 6 shows the torque diagram of a scroll compressor at a pressure ratio of 3 / 20 with a 30° phase offset or angle offset. This angle offset is between the characteristic curve of the required torque (refer to the solid line, hereinafter abbreviated as "RT" - required torque) and the characteristic curve of the actually provided torque (refer to the dashed line, hereinafter abbreviated as "AT" - actual torque). The angle offset characterized between the maximum of RT and the maximum of AT can be well recognized. As soon as the value of RT exceeds the value of AT, the vibration increases (refer to the third thin solid line). When RT and AT intersect, the vibration is 0 Newton. The vibration has a maximum amplitude value of 15 N (between the maximum and the minimum).

[0032] Figure 7 shows the torque diagram of the scroll compressor at a pressure ratio of 3 / 20, similar to that in Figure 6, but in this case it has a phase offset of 60°. The vibration has a maximum amplitude value (between maximum and minimum) of 28 N.

[0033] Figure 8 shows the torque diagram of the scroll compressor at a pressure ratio of 3 / 20, similar to that in Figure 6, but in this case it has a phase offset of 10°. The vibration has a maximum amplitude value (between maximum and minimum) of 5 N.

[0034] Figure 9 shows the torque diagram of the scroll compressor at a pressure ratio of 3 / 20 and an amplitude offset (English: amplitude error). The vibration has a maximum amplitude value (between maximum and minimum) of 7 N. In this case, the characteristic curves RT and AT have the same phase and there is no phase shift or phase offset as in Figures 6 to 8. This means that the maximum and minimum are at equal orbital angles, i.e., 60 degrees and 200 degrees in this case. When RT and AT intersect, the vibration is also zero.

[0035] Figure 10 shows the torque diagram of the scroll compressor according to the ratio of the outlet pressure p in to the inlet pressure p out , and in that case, five characteristic curves are shown for different outlet pressures. The maximum of all five characteristic curves is at about 2.8 of p out versus p in .

[0036] Figure 11 shows a diagram of the torque deviation according to the ratio of the outlet pressure p in to the inlet pressure p out , and in that case, five characteristic curves are shown for different outlet pressures. The maximum of all five characteristic curves is at about 12 of p out versus p in .

[0037] Figure 12 shows the torque diagram of a scroll compressor having a number of different characteristic curves according to the orbiting track angle from 0 degrees to 360 degrees. The various characteristic curves 1 to 15 represent the compression ratio of the inlet pressure to the outlet pressure. The lower characteristic curves 1 to 4 show a generally unchanged transition, but in the higher characteristic curves, for example 11 to 15, very distinct maximum and minimum values can be seen with respect to the required torque.

Claims

1. A method for controlling a scroll compressor having first and second spirals disposed concentrically with each other, wherein the first spiral is movable relative to the second spiral for decompression driving or compression driving of the scroll compressor, in which the following steps: - driving a motor to move the first spiral; - measuring a plurality of accelerating forces acting on the scroll compressor, wherein the accelerating forces depend on the relative position and / or the angular position of the first spiral relative to the second spiral; - driving the motor so that the accelerating force is reduced until the measured accelerating force falls below a predetermined value when the measured accelerating force exceeds the predetermined value by adapting the torque transition of the motor according to the measured accelerating force, wherein the torque phase and the torque amplitude provided by the motor shift according to the relative position or the angular position of the first spiral relative to the second spiral, the step of driving the motor so that the accelerating force is reduced; comprising the accelerating force is directly measured using a sensor on a fixed point mount for fixing the housing of the scroll compressor, adapting the torque transition of the motor - shifting the torque phase of the motor in a first direction; - measuring a plurality of the accelerating forces, when the accelerating force increases, shifting the torque phase of the motor in a second direction opposite to the first direction, when the accelerating force decreases, further shifting the torque phase of the motor in the direction at that time until the minimum of the accelerating force is achieved, including the steps of, also, adapting the torque transition of the motor - changing the torque amplitude of the motor in the first direction; - measuring a plurality of the accelerating forces, when the accelerating force increases, changing the torque amplitude of the motor in a second direction opposite to the first direction, when the accelerating force decreases, further changing the torque amplitude of the motor in the direction at that time until the minimum of the accelerating force is achieved, including the steps of, a method for controlling a scroll compressor, characterized in that.

2. In a control device for a scroll compressor having first and second spirals arranged concentrically with each other, the control device operates as follows, that is - controlling a motor to move a first spiral relative to a second spiral for decompression driving or compression driving of the scroll compressor; - detecting a plurality of accelerating forces applied to the scroll compressor as measured values, wherein the accelerating forces depend on the relative position and / or angular position of the first spiral with respect to the second spiral, and - by adapting the torque transition of the motor according to the measured accelerating forces, when the accelerating forces exceed a predetermined value, driving the motor so that the accelerating forces decrease until the measured accelerating forces fall below the predetermined value, and the torque phase and torque amplitude provided by the motor shift according to the relative position or angular position of the first spiral with respect to the second spiral, the accelerating forces are directly measured using a sensor on a fixed point mount for fixing the housing of the scroll compressor, the control device adapts the torque transition of the motor so that the torque phase of the motor is shifted in a first direction, when the detected measured value of the accelerating forces increases, the torque phase of the motor shifts in a second direction opposite to the first direction, and when the detected value of the accelerating forces decreases, the torque phase of the motor further shifts in the direction at that time until the minimum of the accelerating forces is achieved, is designed to be also, the control device adapts the torque transition of the motor so that the torque amplitude of the motor is shifted in the first direction, when the detected measured value of the accelerating forces increases, the torque amplitude of the motor shifts in the second direction opposite to the first direction, and when the detected measured value of the accelerating forces decreases, the torque amplitude of the motor further shifts in the direction at that time until the minimum value of the accelerating forces is achieved, is designed, characterized by a control device for a scroll compressor.

3. A scroll compressor having the control device according to claim 2.

4. A computer-readable memory medium having stored instructions that, when executed by at least one processor, cause the at least one processor to perform the method of claim 1.

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