CN100441872C - Variable capacity rotary compressor and control method thereof - Google Patents

Abstract

A variable capacity rotary compressor, including two cylinders A and B with different working volumes arranged in the compressor casing, pistons and sliding vanes are respectively arranged in the cylinders, partitions are arranged between the cylinders, and the casing is also provided with There is an eccentric crankshaft that drives the piston, and the upper and lower bearings that support the crankshaft. Its structural feature is that a control valve device for controlling the three-stage capacity conversion of the compressor is arranged outside the compressor housing, and the control valve device includes a valve seat arranged in the valve housing. , and the slider crimped on the valve seat, the slider is connected to the crankshaft, and the valve bearing used to support the crankshaft is set in the valve housing, and the motor that drives the crankshaft is arranged. Two output holes A and B of B or two cylinders A and B suction pipes, the crankshaft in the valve is connected with the valve rotor in the motor, and the valve stator in the motor that drives the rotor forward and reverse is set outside the valve housing. The invention has small starting power, low noise, stable operation, good energy-saving effect and human comfort.

Description

Variable capacity rotary compressor and control method thereof

technical field

The invention relates to a variable capacity rotary compressor and a control method thereof, in particular to a variable capacity rotary compressor for an air-conditioning system and a control method thereof.

Background technique

At present, the frequency conversion compressor can change the total cylinder displacement by changing the compressor speed, and the double-cylinder rotary compressor also has a strong advantage in changing the total cylinder displacement through capacity control. In contrast, the capacity control compressor of the same specification has the characteristics of higher efficiency, lower production cost, simpler system control, wider application range and more reliable performance than the compressor using frequency conversion technology.

A common double-cylinder rotary compressor uses two cylinders of the same displacement. When it is working, one of the cylinders is always in a compressed working state, and the other cylinder can either work or not. Two-stage switching between 100% and 50% of the working capacity. However, the two-cylinder rotary compressor with this structure has a relatively large range of changes when it is converting its working capacity, and its energy saving and human comfort are relatively poor.

Contents of the invention

The technical problem to be solved by the present invention is to provide a variable capacity rotary compressor with simple and reasonable structure, low production cost, good energy-saving effect and human comfort, and a control method thereof to overcome the current situation. There are deficiencies in the technology.

The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a variable capacity rotary compressor, including two cylinders A and B arranged in the compressor housing, pistons and sliding vanes are respectively arranged in the two cylinders, and the cylinders A partition is arranged between them, and an eccentric crankshaft for driving the piston is arranged inside the casing, which supports the upper and lower bearings of the crankshaft. The device includes a valve seat set in the valve housing, and a slide block crimped on the valve seat, the slide block is connected to the crankshaft, a valve bearing set in the valve housing for supporting the crankshaft, a motor driving the crankshaft, and the valve seat There are two output holes A and B connected to the slide cavity A and B or the suction pipes of the two cylinders A and B, the crankshaft is connected to the valve rotor in the motor, and the valve stator in the motor drives the rotor forward and reverse It is arranged outside the valve housing; there is a high-pressure pipe on the side of the valve housing, one end of which communicates with the high-pressure chamber in the valve housing, and the other end communicates with the high-pressure chamber of the compressor; among them, the upper and lower bearings, partitions and two Two cylinders A and B respectively enclose slide cavity A and B.

The above-mentioned output hole A communicates with one end of the output pipe A, and the other end communicates with the vane cavity A; one end of the output tube B communicates with the output hole B, and the other end communicates with the vane cavity B; the output holes A and B are connected to the valve seat The upper circumferential direction is arranged at 60°~120°, the through holes E and F are arranged at 60°~120° along the circumferential direction on the slider; the output holes A and B are arranged on the valve seat along the circumferential direction, and the upper edge of the slider There are two through holes E and F corresponding to the output holes A and B respectively in the circumferential direction; an oblong hole is arranged in the center of the slider. any of B.

The above-mentioned control valve device also includes a first input hole C which is arranged at the center of the first valve seat and communicates with the low-pressure side chamber of the compressor; The oblong hole, when the first slider rotates, the length of the first oblong hole meets any one of the first input hole C to the first output hole A or B; one end of the first high-pressure pipe is connected to the high pressure of the compressor or system The chambers communicate with each other, and the other end communicates with the high-pressure side chamber of the valve housing.

The above-mentioned control valve device also includes a second input hole C that is arranged at the center of the second valve seat and communicates with the low-pressure side chamber of the compressor; The oblong hole, when the second slider rotates, the length of the second oblong hole is sufficient to communicate with any one of the second input hole C to the second output hole A or B; one end of the second high-pressure pipe is connected to the high-pressure side chamber of the compressor The other end communicates with the high-pressure side chamber of the valve housing; the second crankshaft and the second valve bearing are connected through threads, the top end of which is in contact with the valve rotor, and the bottom end passes through the second valve bearing and the second slide block After the second oblong hole on the top, it connects with the second input hole C arranged on the second valve seat; the bottom end of the second crankshaft is an inverted cone structure, and the second input hole C matched with it is also an inverted cone structure ; One end of the second high-pressure pipe communicates with the compressor or the high-pressure side chamber of the system, and the other end communicates with the high-pressure side chamber of the valve housing.

The above-mentioned control valve device also includes a third oblong hole arranged at the center of the third slider. When the third slider rotates, the length of the third oblong hole satisfies that it is connected to any one of the third output holes A or B. ; Wherein, the third slider has an inverted T-shaped structure, its top is connected to the third crankshaft, the middle rod-shaped part of the third slider is provided with a vent hole, and the part near the center of the valve housing is provided with a third valve bearing and The middle rod-shaped part of the third slider is socketed, and an upper chamber is formed between the upper part of the third valve bearing and the inner wall of the valve housing. The upper end of the vent hole is located at the part where the upper chamber is located. The third high-pressure pipe communicates with the high-pressure chamber of the compressor; the lower chamber is formed between the bottom of the third valve bearing and the inner wall of the valve housing, and a third input pipe is arranged on the side of the lower chamber, and the third input pipe is connected to the compressor or The low pressure of the system is connected; one end of the output pipe A communicates with the output hole A, the other end communicates with the suction pipe of the cylinder A, one end of the output pipe B communicates with the output hole B, and the other end communicates with the suction pipe of the cylinder B; the third The output holes A and B are arranged on the third valve seat in the circumferential direction, and the third slider is provided with two third through holes E and F corresponding to the output holes A and B in the circumferential direction.

The above-mentioned control valve device includes a cylindrical cylinder arranged at the lower part of the valve housing, a fourth slider is arranged in the cylinder, the fourth slider is connected with the fourth crankshaft, the upper part of the fourth crankshaft is threaded, and the side of the cylinder is provided with a second Four output pipes A, fourth output pipe B and fourth input pipe; the fourth output pipe A and the fourth output pipe B are respectively connected to the slide chambers of cylinders A and B of the compressor, and the fourth input pipe is connected to the compressor The suction pipe, the fourth high-pressure pipe set on the valve housing communicates with the high-pressure chamber of the compressor; the fourth slider has two upper and lower layers, the fourth crankshaft is connected in series with the entire fourth slider, and the cylindrical cylinder is connected with the upper and lower layers. The sliders respectively enclose the upper, middle and lower cavities. The fourth crankshaft is provided with a channel connecting the upper and lower cavities. The upper and lower cavities are high-pressure chambers, and the middle cavity is In the low-pressure chamber, the fourth output pipe A and the fourth output pipe B communicate with the upper and lower chambers respectively, and the fourth input pipe communicates with the middle low-pressure chamber.

The above-mentioned cylinders A and B have different displacements. There is a spring on the back of the sliding vane of the small displacement cylinder to press the sliding vane on the piston side, and there is no spring on the back of the sliding vane of the large displacement cylinder.

A variable capacity rotary compressor control method, characterized in that the control valve device realizes three types of pressure switching through the three-step action of the slider, and finally outputs it to the sliding vane cavity or cylinder of the compressor to realize the three-stage capacity conversion Control: When the vane chamber pressure is switched, the two output ports of the control valve device are respectively connected with the vane chambers of the compressor cylinders A and B, and the first input port of the control valve device is connected with the compressor or system When the pressure of the low pressure side of the control valve device is connected, the second input hole of the control valve device is connected with the high pressure side of the compressor or the system, wherein the internal pressure of the compressor shell is used as the high pressure side of the system; the control valve device is driven by the motor to move upward The three-step action of the set slider makes the pressure of the two output holes switch back and forth between the high-pressure side and the high-pressure side, the high-pressure side and the low-pressure side, and the low-pressure side and the high-pressure side, respectively, to realize the compressor Three-stage capacity switching control; or, when it is cylinder pressure switching mode, the two output holes of the control valve device are respectively connected with the suction pipes of the compressor cylinders A and B, and the first input hole of the control valve device is connected with the When the pressure of the high pressure side of the compressor or the system is connected, and the second input hole is connected with the pressure of the low pressure side of the compressor or the system, the control valve device drives the three-step action of the slider set on it through the motor, so that the two The pressure of each output hole is switched back and forth between the low-pressure side and the low-pressure side, the low-pressure side and the high-pressure side, and the high-pressure side and the low-pressure side to realize the three-stage capacity conversion control of the compressor; among them, the two cylinders A And B displacement size is different.

When the above-mentioned sliding vane chamber pressure switching mode is used, the control valve device drives the three-step action of the slider set on it through the motor, and communicates with any one of the first input hole and the two output holes, or does not communicate with each other. , and communicate with the second input hole and the two output holes at the same time, or connect the second input hole with any one of the two output holes, so that the pressure of the two output holes is respectively on the high pressure side and the high pressure side, and on the high pressure side and the low pressure side. side, low-pressure side and high-pressure side to switch back and forth between the three modes to realize the three-stage capacity conversion control of the compressor; or, when the cylinder pressure is switched, the control valve device drives the slider set on it through the motor. The action of three steps connects the first input hole and the two output holes or any one of them; and connects the second input hole and any one of the two output holes at the same time, or is not connected, so that the two output holes The pressure of the compressor is switched back and forth between the low-pressure side and the low-pressure side, the low-pressure side and the high-pressure side, and the high-pressure side and the low-pressure side to realize the three-stage capacity conversion control of the compressor.

The three modes in the above-mentioned three-stage capacity conversion control can be alternately switched back and forth sequentially, or any mode in the middle can be removed, and only the remaining two modes can be directly switched back and forth.

The capacity of the running capacitor required by the motor of the above-mentioned variable capacity rotary compressor adopts two types, Rc2 and Rc3, where Rc3<Rc2, if the compressor with three-stage capacity control is divided into three types according to the working capacity, then the minimum The working capacity mode corresponds to the capacitor Rc3 with a smaller capacity, the larger working capacity mode corresponds to the larger capacity capacitor Rc2, and the maximum working capacity mode corresponds to the superposition Rc3+Rc2 of the smaller capacity capacitor and the larger capacity capacitor; or without changing In the compressor capacity mode, the capacity of the motor run capacitor is switched.

The present invention adopts three-step control to make the pressure in the slide cavity, or control the cylinder pressure to switch independently between high and low pressure, wherein the basic key of the three steps is to set two output holes for pressure switching on the slider and an input hole for low or high pressure,

When using the sliding vane chamber pressure switching method, the pressure of the two output holes is switched between high pressure side and high pressure side, high pressure side and low pressure side, and low pressure side and high pressure side.

When the cylinder pressure switching method is used, the pressure of the two output holes is switched between the low-pressure side and the low-pressure side, the low-pressure side and the high-pressure side, and the high-pressure side and the low-pressure side.

When the compressor or the system is in operation, by controlling the change of the working time in each mode, the cooling capacity can be adjusted steplessly per unit of time.

The invention has small starting power, low noise, stable operation, good energy-saving effect and human comfort.

Description of drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Fig. 2 is a partial cross-sectional enlarged structural schematic diagram of a compressor and a control valve in the sliding vane pressure switching mode.

Fig. 3-Fig. 5 are schematic diagrams showing three kinds of working state structural diagrams of X-X cross-sectional enlargement in Fig. 2 .

Fig. 6 is a cross-sectional enlarged structural schematic diagram of the control valve at low reversing torque.

FIG. 7 is a schematic diagram of the Y-Y cross-sectional structure in FIG. 6 .

Fig. 8 is a partial cross-sectional enlarged structural schematic diagram of a compressor and a control valve in a cylinder pressure switching mode.

FIG. 9 is a schematic diagram of the Z-Z section structure in FIG. 8 .

Figure 10 is a partial working circuit diagram of the compressor

Fig. 11-Fig. 13 are schematic cross-sectional enlarged structure diagrams of the piston control valve in the slide chamber pressure switching mode.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

In the figure, 1 is the rotary compressor, 2 is the high-pressure outlet pipe, 3 is the condenser, 4 is the expansion valve, 5 is the evaporator, 6 is the liquid receiver, 7 is the control valve, 10 is the cylinder A, and 11 is the cylinder B, 12 is the separator, 13 is the upper bearing, 14 is the lower bearing, 15 is the slide cavity A, 16 is the slide cavity B, 17 is the spring, 21 is the cylindrical shell,

22 is the first valve seat, 22' is the second valve seat, 22 "is the third valve seat,

23 is the first slider, 23' is the second slider, 23 "is the third slider, 23'" is the fourth slider,

23.1 is the first through hole F, 23.1' is the second through hole F, 23.1 "is the third through hole F,

23.2 is the first through hole E, 23.2' is the second through hole E, 23.2 "is the third through hole E,

24 is the first crankshaft, 24' is the second crankshaft, 24 "is the third crankshaft, 24'" is the fourth crankshaft,

25 is the first valve bearing, 25' is the second valve bearing, 42 is the third valve bearing,

26 is the valve rotor, 27 is the valve stator,

28 is the output tube A, 28'" is the fourth output tube A,

29 is the output tube B, and 29'" is the fourth output tube B,

30 is the first high-pressure pipe, 30' is the second high-pressure pipe, 30 "is the third high-pressure pipe, and 30'" is the fourth high-pressure pipe,

31 is the input pipe, 31'" is the fourth input pipe,

32 is the first oblong hole, 32 ' is the second oblong hole, and 32 " is the third oblong hole,

33 is the first output hole A, 33' is the second output hole A, 33 "is the third output hole A, 33'" is the fourth output hole A,

34 is the first output hole B, 34' is the second output hole B, 34 "is the third output hole B, 34'" is the fourth output hole B,

35 is the first input hole C, 35' is the second input hole C, 35'" is the fourth input hole C,

37 is a ventilation hole, 38 is an upper chamber, 39 is a lower chamber, 40 is a suction pipe A, 41 is a suction pipe B, 43 is a third input pipe C, 45 is a communication hole,

50 is a cylindrical cylinder, 51 is a passage, 52 is an upper cavity, and 53 is a lower cavity.

Referring to Figure 1, it is a diagram of the refrigerating cycle system in which the variable capacity rotary compressor is installed in the refrigerating and heating air conditioners, and the refrigerating system during cooling is introduced here. The compressor 1 sucks low-pressure gas from the accumulator, compresses it, and discharges the high-pressure gas from the high-pressure outlet pipe 2 . Afterwards, the liquid refrigerant condensed by the condenser 3 is decompressed by the expansion valve 4, evaporated by the evaporator 5, and returned to the liquid receiver 6 as a low-pressure refrigerant, and is sucked by the compressor again and compressed. Here, the control valve device 7 is installed outside the compressor. Its function is to make the variable displacement rotary compressor with two cylinders in operation, and the independent cylinders continue to compress or stop working, so that the compressor can refrigerate during operation. The ability is switched to three stages. Therefore, the two cylinders have different displacements.

For example, in the cooling operation of the air conditioner, when rapid cooling is required, such as when the compressor is required to exert the highest cooling capacity in midsummer high temperature weather, it should be operated at the maximum mode; when the room temperature drops close to the target temperature, the compressor should be operated Switch to intermediate capacity, operate in the intermediate mode, and reduce the cooling capacity; when the room temperature further reaches the target temperature, it needs to switch to low cooling capacity operation, and operate in the minimum mode. Therefore, according to the cooling load, the cooling capacity can be switched at any time, which can not only perform comfortable air conditioning, but also prevent the waste of cooling capacity and improve the efficiency of the air conditioning.

In other words, the variable capacity rotary compressor, that is, the rotary compressor with capacity control has the same capacity control function as the rotary compressor using the frequency converter.

Two methods of switching the control capability of the rotary compressor with two cylinders will be described below: "Slide chamber pressure switching method" and "Cylinder pressure switching method".

In the following, the way of switching the pressure of the vane chamber will be introduced first, and then the way of switching the pressure of the cylinder will be introduced.

Slide chamber pressure switch mode

When the operation and stop of the cylinder is controlled by the pressure switching mode of the sliding vane chamber, it is first necessary to switch the pressure of the sealing vane chamber between high pressure and low pressure. If the sliding vane cavity is on the high pressure side, as in the common rotary compressor, the sliding vane presses against the outer surface of the piston for compression. However, if the vane cavity is on the low pressure side, the vane will not slide out of the vane cavity without compression. In this case, the piston rotates but does not compress, creating idle motion.

Referring to Fig. 2-Fig. 5, there are two cylinders A10 and B11 arranged in the rotary compressor with two cylinders, and their sliding vane cavity (that is, the cavity part at the back of the sliding vane) passes through the partition plate 12 and the upper part of the cylinder. , The next two bearings 13 and 14 are sealed to form the sliding vane cavity A15 and the sliding vane cavity B16. Among them, a spring 17 for pressing the slide on the piston side is provided in the slide cavity B of the cylinder with a small displacement, and the control valve device 7 attached to the outside of the casing of the compressor includes a first valve seat set in the valve casing 21. 22, and the first slider 23 crimped on the first valve seat 22, the first slider 23 is connected to the first crankshaft 24, and is set in the valve housing 21 to support the first valve of the first crankshaft 24 Bearing 25, the motor that drives the first crankshaft 24 to run, the first crankshaft 24 is connected to the valve rotor 26 in the motor, and the valve stator 27 that drives the rotor forward and reverse in the motor is arranged on the outside of the valve housing 21; the motor is a stepper The motor can detect the rotation angle of the valve rotor. The first valve seat 22 is provided with the first output hole A33 and the first output hole B34 connected to the slide chamber A15 and the slide chamber B16, and the first output hole A33 and B34 are along the circumference of the first valve seat 22. Arranged at 60°-120°; the first through holes E23.2 and F23.1 are arranged on the first slider 23 along the circumferential direction at 60°-120°, and the first through holes E23.2 and F23.1 are respectively Corresponding to the first output holes A and B; there is a first high-pressure pipe 30 on the side of the valve housing 21, one end of which communicates with the high-pressure chamber in the valve housing 21, and the other end communicates with the high-pressure chamber of the compressor; control The valve device also includes a first input hole C35 arranged at the center of the first valve seat 22 and communicated with the low-pressure side chamber of the compressor; a first oblong hole communicated with the first input hole C35 is arranged at the center of the first slider 23 Holes 32, wherein the length of the first oblong hole 32 is such that it connects the first input hole C35 to any one of the first output holes A33 or B34. One end of the output tube A28 communicates with the first output hole A33, and the other end communicates with the vane cavity A15. One end of the output tube B29 communicates with the first output hole B34, and the other end communicates with the vane cavity B16. The inside of the cylindrical shell 21 is the high pressure side, the input pipe 31 is connected to the low pressure side such as the suction pipe, and the first input hole C35 is the low pressure side.

The first oblong hole 32 on the first slider 23 is sealed, because the first input hole C35 is on the low pressure side, so the pressure in the first oblong hole is low pressure.

The first slider 23 is rotated at an interval of 60-120° by a stepping motor, and 120° is selected in this embodiment.

When the control valve is in the maximum mode, see FIG. 3 , the rotation angle of the first oblong hole 32 is 0°. That is to say, the first oblong hole 32 is 120° from the first output hole A33 and the first output hole B34 respectively, so it does not communicate with the first output hole A33 or the first output hole B34. However, the first output holes A33 and B34 are consistent with the first through holes E23.2 and F23.1 on the first slider, so the two holes are open, and the pressure and cylinder pressure of the first output holes A and B The internal pressure of the casing 21 is the same, which is the high pressure side.

When the first slider 23 rotates 120° clockwise, it enters the middle mode, as shown in FIG. 4 , the first oblong hole 32 communicates with the first output hole B34, and the first output hole B34 is the low pressure side. On the other hand, since the first output hole A33 is open, the first output hole A33 is on the high voltage side.

When the first slider 23 rotates clockwise for another 120°, it enters the minimum mode. At this time, the first oblong hole 32 communicates with the first output hole A33, and the first output hole A33 is the low pressure side. On the other hand, the first output hole B34 is in an open state, and the first output hole B34 is a high-voltage side.

Let’s sort out the above content below. When the first oblong hole 32 of the first slider 23 is in the maximum mode and is in a position not connected to the first output hole A33 or B34, the output pipe A28 and the output pipe B29 are the high pressure side. Vane chamber A and vane chamber B are the high pressure side. Cylinders A and B have sliding vanes to slide out and enter the normal compression working state.

When the first oblong hole 32 of the first slider 23 is in the middle mode, the first slider 23 is in the position communicating with the first output hole B34, the output pipe B29 is the low pressure side, but the output pipe A28 is the high pressure side, so the slider Chamber A is the high pressure side, and slide chamber B is the low pressure side. Therefore, cylinder A has the sliding vane to slide out and enter the normal compression working state. However, the slider of cylinder B cannot be slid out, and is accommodated in the slider chamber without compression.

When the first oblong hole 32 of the first slider 23 is in the minimum mode, it is in a position communicating with the first output hole A33, the output pipe B29 is the high-pressure side, the output pipe A28 is the low-pressure side, and the cylinder A is in a non-working state. B is the working state.

For the switch combination of double cylinders, three kinds of capacity control can be carried out. In addition, as mentioned above, rotating the sliders 120° respectively can switch the modes in the order of 1, 2 and 3,

If you need to switch back and forth between the maximum mode and the middle mode, that is to say, switch back and forth from the maximum mode to the middle mode, you must first rotate the slider 120° clockwise from the maximum mode to the middle mode, and then Rotate 240° to return to maximum mode. Going round and round, you can repeat the maximum mode and the middle mode, just make the slider rotate 240° in order to omit the unnecessary minimum mode in the middle. This is a very important function in actual system control.

6-7, the second oblong hole 32' of the second slider 23' is the low pressure side, but the outside of the second slider 23' is the high pressure side. Therefore, the second slider 23' is pressed above the second valve seat 22' to generate a thrust force. When the torque of the stepping motor is sufficiently large, the thrust force can be overcome to make the second slide block 23' rotate, but when the torque is small, the second slide block 23' cannot be driven to rotate. If the internal and external pressure of the second sliding block 23' can be balanced, the second sliding block 23' can be driven to rotate with a small torque.

By threaded connection between the second crankshaft 24' and the second valve bearing 25', its top end is connected with the valve rotor 26, and its bottom end passes through the second oblong circle on the second valve bearing 25' and the second slide block 23' After the hole 32', it connects with the second input hole C35' arranged on the second valve seat 22'; the bottom end of the second crankshaft 24' is an inverted cone structure, and the second input hole C35' matched with it is also an inverted Conical structure. Due to the threaded connection between the second crankshaft 24' and the second valve bearing 25', when the valve rotor 26 rotates, the second crankshaft 24' can open or close the second input hole C35' while moving up and down.

When the compressor is running, the second inlet port C35' is always open. When the compressor switches modes during operation, firstly, the second crankshaft 24' rotates clockwise to close the second input hole C35'. Therefore, no matter the second slide block 23 ' is in the maximum mode, any position of the intermediate mode or the minimum mode, the internal pressure of the second slide block 23 ' is high pressure; that is because the space volume of the second slide block 23 ' is small, and the The gas seal on the surface of the second valve seat 22' is not completely tight. When the internal pressure of the second slider 23' is on the high-pressure side, the second slider 23' no longer generates thrust, so a small torque can make the second slider 23' 23' free spins.

When the second slider 23' rotated to the specified position, the second crankshaft 24' rotated to the left to open the second input hole C35', so the second oblong hole 32' of the second slider 23' was the low pressure side, The thrust force is generated on the second slide block 23' again, and the second slide block 23' is fixed on the second valve seat 22' again. This completes the mode switch.

When either cylinder in the two-cylinder rotary compressor starts to compress, the casing pressure begins to rise, and the sliding vane of the other cylinder slides out at the same time for compression. Therefore, the spring in one of the cylinders can be omitted.

If a spring is arranged in the cylinder with a small displacement, the compression during start-up starts from the cylinder with a small displacement, and the start-up load is small, which has the advantages of reducing the torque of the motor and reducing the vibration of the compressor.

For the same reasons as above, it is recommended that the compressor be switched to a cylinder with a smaller displacement before shutting down when the compressor is shut down. If the minimum mode is used as the state of minimum capacity, then the vibration generated when the compressor stops can be minimized by using the minimum mode to stop.

Referring to Fig. 8, the cylinder pressure switching mode is a method for switching the pressure connected to the inlet suction pipe of the cylinder between low pressure and high pressure. Normal compression can be performed at low pressure, but at high pressure, the vane and piston cannot be compressed and are stored in the vane cavity. That is to say, although the piston can rotate, it is only idling, and there is no compression.

Wherein, the third slider 23 "is an inverted T-shaped structure, and its top is connected with the third crankshaft 24 ", and the rod-shaped part of the middle part is provided with a vent hole 37, and the lower end of the vent hole 37 is provided with a third input hole. The part near the center of the body 21 is provided with a third valve bearing 42 which is socketed with the rod-shaped part in the middle of the third slide block 23 ", and an upper chamber 38 is formed between the top of the third valve bearing 42 and the inner wall of the valve housing 21, and the vent hole The upper end of the 37 is provided with a communication hole 45 at the part where the upper chamber 38 is located, and the side of the upper chamber 38 is provided with a high-pressure pipe 30 "communicating with the high-pressure chamber of the compressor; A lower chamber 39 is formed, and a third input pipe 43 is arranged on the side of the lower chamber 39 , and the third input pipe 43 communicates with the outlet of the liquid reservoir 6 . The communication hole 45 and the third input hole are on the high pressure side; the lower chamber 39 is on the low pressure side

The third slider 23" will rotate clockwise at intervals of 120° as shown in Fig. 3-Fig. "It is the same in principle, but the difference is that the pressure of the output hole and the input hole are opposite.

If the minimum cooling capacity is the minimum mode, then we can easily know that reducing the displacement of cylinder B will result in a decrease in the minimum cooling capacity of the entire compressor. However, when the total displacement of cylinder A+B is constant, if the displacement of cylinder B is reduced alone, the displacement of cylinder A will increase, and the capacity difference between the maximum mode and the middle mode becomes smaller; on the other hand , the capability difference between the intermediate mode and the minimum mode becomes larger. If the minimum cooling capacity is reduced as much as possible, the variable range of capacity that can be achieved by the compressor can be widened, but the poor balance of capacity between modes will deteriorate, and its direct disadvantage will be that the effect of the three-stage capacity control will be overall weakened.

The following shows that the total displacement of cylinder A+B is constant, and when the displacement of cylinder B is changed, the minimum mode operation (minimum capacity) and COP (refers to the energy efficiency ratio of the compressor, that is, the ratio of the cooling capacity of the compressor to the input electric power than) the relationship between. Here, Vd=displacement of cylinder A (Vd1)+displacement of cylinder B (Vd2), the experimental results and simulation results show that when Vd=1, Vd1=0.6～0.7, Vd2=0.4～0.3, the seasonal energy consumption it's the best. For example, if the displacement of cylinder A is 7.0cc, and the displacement of cylinder B is 3.0cc, when compressing cylinders A and B (maximum mode), the displacement is 10cc and operates at 100% capacity; if only cylinder A is compressed ( Intermediate mode), the displacement is 7.0cc, and operates at 70% of capacity; if only compression cylinder B (minimum mode), the displacement is 3.0cc, and operates at 30% of capacity.

Referring to Fig. 10, in order to increase the torque of the compressor motor and improve the efficiency of the rotary compressor, a running capacitor RC is usually used, but the capacity of the capacitor needs to be optimized according to the running load of the compressor. Therefore, the three-stage capacity control rotary compressor also needs to select the best capacitor capacity according to various modes. In the figure, the capacitor capacity selection method for improving efficiency when the control cost rises is shown. That is, Rc3 is selected in the minimum mode with the least operating load, Rc2 is selected in the middle mode with a small operating load, and Rc2+ is selected in the maximum mode with the largest load. Rc3, to expand the capacity of the capacitor.

However, if the outdoor temperature is very high during the cooling operation of the air conditioner, the operating load is greater than the capacity of the compressor, or the voltage is abnormally low. In this kind of abnormal situation, sometimes the operation of the maximum mode cannot be continued, but can only be switched to the middle mode. However, when the motor torque is insufficient when the middle mode is running, the capacity of the running capacitor can only be selected to be the same as the maximum mode, as Rc2+Rc3, to make up for the lack of motor torque.

On the contrary, when the operation load of the compressor in the maximum mode or the medium mode operation is small, the running capacitors of the medium mode and the minimum mode can be used respectively to improve the motor efficiency. In order to improve the efficiency of the compressor and the motor, at least two kinds of running capacitors should be prepared, and the best combination of running capacitors should be selected.

The bottom shows the stepless adjustment of the capacity of the compressor or system by changing the operating time in each mode within a certain period. Set the cooling capacity per unit time of cylinder A+cylinder B as Q', the cooling capacity of cylinder A per unit time as Qa; the cooling capacity of cylinder B per unit time as Qb; The operating time is T'; the operating time in the cylinder A mode is Ta; the operating time in the cylinder B operating mode is Tb; then the cooling capacity of the compressor within the time T is: Q=Q'×T'+Qa×Ta+Qb× Tb; the compressor has downtime during the time T, so T≥T'+Ta+Tb; due to the different cooling capacity of the compressor or system in each mode, by changing the composition ratio of the operating time per unit time in each mode, the compression Combined with the shutdown of the compressor, the stepless adjustment of the cooling capacity of the compressor from the minimum 0 to the maximum Q'×T is realized.

Referring to Fig. 11-Fig. 13, the sliders mentioned above are all rotating, and the reciprocating operation of the slider will be briefly described below. The control valve device includes a cylindrical cylinder 50 arranged at the bottom of the valve housing 21, a fourth slide block 23 "' is arranged in the cylinder, the fourth slide block 23 "' is connected with the fourth crankshaft 24 "', and the fourth crankshaft The upper part of 24"' is threaded, and the side of the compressor cylinder is provided with the fourth output pipe A28"', the fourth output pipe B29"' and the fourth input pipe 31"'; the fourth high pressure pipe 30"'; the fourth output pipe A28 "' and the fourth output pipe B29"' are respectively connected to the slide chambers of cylinders A and B of the compressor. In addition, the fourth input pipe 31"' is connected to the suction pipe of the compressor, and the fourth high-pressure pipe 30"' is connected to the compressor's The high-pressure chamber communicates; the fourth slide block 23 "' is two upper and lower layers, and the fourth crankshaft 24 "' connects the entire slide block in series. cavity, the fourth crankshaft 24"' is provided with a channel 51 communicating with the upper cavity 52 and the lower cavity 53, the upper and lower cavities are both high-pressure chambers, that is, the high-pressure side Pd; the middle cavity is a low-pressure cavity The chamber, that is, the low-pressure side Ps, the fourth output pipe A28"' and the fourth output pipe B29"' communicate with the upper and lower high-pressure cavities respectively, and the fourth input tube communicates with the middle low-pressure cavity. The fourth slider 23" The two ends of ' are disc-shaped, and there is a small gap between the cylinder wall and the cylinder wall when it moves up and down. On the other hand, the crankshaft on the upper part of the fourth slider 23"' is a threaded structure. When the valve rotor 26 drives the fourth crankshaft 24"' to rotate, the fourth slider 23"' can move up and down. The piston stroke 1 The four output pipes A28″’ and B29″’ are located on the high pressure side, which is the maximum mode; in stroke 2, the fourth output pipe A28″’ is on the high pressure side, and the fourth output pipe B29″’ is on the low pressure side, which is the middle mode; stroke 3 On the contrary, the fourth output tube B29"' is on the high-voltage side, but the fourth output tube A28"' is on the low-voltage side, which is the minimum mode.

The above is an example of three-stage mode switching by switching the pressure of the output pipes A28"' and B29"' into three states through the up and down reciprocating movement of the disc-shaped fourth slide block 23"' in the cylindrical cylinder.

Claims (12)

1. A variable-capacity rotary compressor comprises two cylinders A and B (10 and 11) arranged in a compressor shell, wherein a piston and a slide sheet are respectively arranged in the two cylinders, a partition plate (12) is arranged between the cylinders, an eccentric crankshaft for driving the piston is also arranged in the shell, and upper and lower bearings (13 and 14) for supporting the crankshaft are also arranged in the shell, the variable-capacity rotary compressor is characterized in that a control valve device for controlling the three-section capacity conversion of the compressor is arranged outside the compressor shell, the control valve device comprises a valve seat arranged in the valve shell (21) and a slide block pressed on the valve seat, the slide block is connected with the crankshaft, a valve bearing for supporting the crankshaft is arranged in the valve shell, a motor for driving the crankshaft to operate is arranged on the valve seat, two output holes A and B connected with slide sheet cavities A and B (15 and 16) or suction pipes of the two cylinders A and B (10 and 11) are arranged on the, a valve stator (27) for driving the rotor to rotate forwards and backwards in the motor is arranged outside the valve shell (21); the side surface of the valve shell (21) is provided with a high-pressure pipe, one end of the high-pressure pipe is communicated with a high-pressure chamber in the valve shell (21), and the other end of the high-pressure pipe is communicated with the high-pressure chamber of the compressor; the upper bearing, the lower bearing, the partition plate and the two cylinders A and B respectively enclose sliding vane cavities A and B (15 and 16).

2. A variable capacity rotary compressor according to claim 1, wherein an output pipe a has one end communicating with the output port a and the other end communicating with the vane chamber a (15), and an output pipe B has one end communicating with the output port B and the other end communicating with the vane chamber B (16); the output holes A and B are arranged on the valve seat at an angle of 60-120 degrees along the circumferential direction, and the through holes E and F are arranged on the sliding block at an angle of 60-120 degrees along the circumferential direction; the output holes A and B are arranged on the valve seat along the circumferential direction, and the sliding block is provided with two through holes E and F corresponding to the output holes A and B respectively along the circumferential direction; the center of the sliding block is provided with a long round hole, and when the sliding block rotates, the length of the long round hole meets the requirement that the long round hole is communicated with any one of the output holes A or B.

3. A variable capacity type rotary compressor according to claim 2, wherein said control valve means further comprises a first input hole C (35) provided at the center of the first valve seat (22) and communicating with a chamber on a low pressure side of the compressor; a first long circular hole (32) communicated with the first input hole C (35) is formed in the center of the first sliding block (23), and when the first sliding block rotates, the length of the first long circular hole is enough to communicate the first input hole C with any one of the first output holes A (33) or B (34); one end of the first high-pressure pipe (30) is communicated with the high-pressure side cavity of the compressor, and the other end of the first high-pressure pipe is communicated with the high-pressure side cavity of the valve shell (21).

4. A variable capacity type rotary compressor according to claim 2, wherein said control valve means further comprises a second inlet hole C (35 ') provided at the center of the second valve seat (22') to communicate with a chamber on a low pressure side of the compressor; a second long circular hole (32 ') communicated with the second input hole C (35 ') is formed in the center of the second sliding block (23 '), and when the second sliding block rotates, the length of the second long circular hole is enough to communicate the second input hole C with any one of the second output holes A (33 ') or B (34 '); one end of the second high-pressure pipe (30') is communicated with the high-pressure side cavity of the compressor, and the other end is communicated with the high-pressure side cavity of the valve shell (21); the second crankshaft (24 ') and the second valve bearing (25') are connected through threads, the top end of the second crankshaft is connected with the valve rotor (26), and the bottom end of the second crankshaft is connected with a second input hole C (35 ') arranged on the second valve seat (22') after passing through the second valve bearing and a second long circular hole (32 ') formed in the second sliding block (23'); the bottom end of the second crankshaft is of an inverted cone structure, and a second input hole C matched with the second crankshaft is also of an inverted cone structure; the second high pressure pipe (30') has one end communicating with the high pressure side chamber of the compressor or system and the other end communicating with the high pressure side chamber of the valve housing (21).

5. The variable capacity type rotary compressor according to claim 2, wherein the control valve means further comprises a third long circular hole (32 ") provided at the center of the third slider (23") and having a length sufficient to communicate with either one of the third output holes a (33 ") or B (34") when the third slider is rotated; the third sliding block (23 ') is of an inverted T-shaped structure, the top of the third sliding block is connected with a third crankshaft (24'), a middle rod-shaped part of the third sliding block is provided with a vent hole (37), a part of the valve housing (21) close to the center is provided with a third valve bearing (42) which is sleeved with the middle rod-shaped part of the third sliding block, an upper cavity (38) is enclosed between the upper part of the third valve bearing and the inner wall of the valve housing, the part of the upper end of the vent hole, which is located in the upper cavity, is provided with a communication hole (45), and the side surface of the upper cavity is provided with a third; a lower cavity (39) is enclosed between the lower part of the third valve bearing and the inner wall of the valve shell, a third input pipe (43) is arranged on the side surface of the lower cavity, and the third input pipe is communicated with a compressor or a low-pressure outlet of a system; one end of the output pipe A is communicated with the output hole A, the other end of the output pipe A is communicated with the suction pipe of the cylinder A (10), one end of the output pipe B is communicated with the output hole B, and the other end of the output pipe B is communicated with the suction pipe of the cylinder B (111); the third output holes A and B are arranged on the third valve seat along the circumferential direction, and the third sliding block is provided with two third through holes E and F corresponding to the output holes A and B along the circumferential direction.

6. A variable capacity type rotary compressor in accordance with claim 1, wherein said control valve means comprises a cylindrical cylinder (50) provided at a lower portion of the valve housing (21), a fourth slider (23 ' ") provided in the cylinder, the fourth slider being connected to a fourth crankshaft (24 '"), the upper portion of the fourth crankshaft being threaded, and a fourth outlet pipe a (28 ' "), a fourth outlet pipe B (29 '") and a fourth inlet pipe (31 ' ") being provided at a side of the cylinder; the fourth output pipe A and the fourth output pipe B are respectively connected with sliding vane cavities of cylinders A and B (10 and 11) of the compressor, in addition, the fourth input pipe is connected with a compressor suction pipe, and a fourth high-pressure pipe (30') arranged on a valve shell is communicated with a high-pressure cavity of the compressor; the fourth sliding block is divided into an upper layer and a lower layer, the fourth crankshaft is connected with the whole fourth sliding block in series, the cylindrical cylinder and the upper and lower layers of sliding blocks respectively enclose an upper cavity, a middle cavity and a lower cavity, a channel (51) for communicating the upper cavity with the lower cavity (52 and 53) is arranged in the fourth crankshaft, the upper cavity and the lower cavity are both high-pressure chambers, the middle cavity is a low-pressure chamber, the fourth output pipe A and the fourth output pipe B are respectively communicated with the upper cavity and the lower cavity, and the fourth input pipe is communicated with the middle low-pressure chamber.

7. A variable capacity type rotary compressor according to claim 1, wherein the cylinders a and B (10 and 11) have different displacements, a spring (17) pressing the vane against the piston is provided on the back of the vane of the cylinder having the small displacement, and no spring is provided on the back of the vane of the cylinder having the large displacement.

8. A control method of a variable-capacity rotary compressor is characterized in that: the control valve device realizes three kinds of pressure switching through the actions of three steps of the sliding block, and finally outputs the three kinds of pressure switching to a sliding sheet cavity or a cylinder of the compressor to realize three-section type capacity switching control:

when the pressure switching mode is adopted, two output holes of the control valve device are respectively communicated with the sliding vane cavities of the compressor cylinders A and B, and a first input hole of the control valve device is communicated with the low-pressure side pressure of the compressor or the system, a second input hole of the control valve device is communicated with the high-pressure side of the compressor or the system, wherein the internal pressure of the shell of the compressor is taken as the high-pressure side of the system; the control valve device drives the three-step action of the sliding block arranged on the control valve device through a motor, so that the pressure of the two output holes is switched back and forth between three modes of a high-pressure side, a low-pressure side and a low-pressure side, as well as the low-pressure side and the high-pressure side, and the three-section type capacity conversion control of the compressor is realized;

or,

when the cylinder pressure switching mode is adopted, two output holes of the control valve device are respectively communicated with suction pipes of a compressor cylinder A and a compressor cylinder B, a first input hole of the control valve device is communicated with the high-pressure side pressure of the compressor or the system, and a second input hole of the control valve device is communicated with the low-pressure side pressure of the compressor or the system, the control valve device drives a sliding block arranged on the control valve device to act in three steps through a motor, so that the pressures of the two output holes are respectively switched back and forth between three modes of the low-pressure side and the low-pressure side, the low-pressure side and the high-pressure side, and the high-pressure side and the low-pressure side, and the three;

wherein the two cylinders A and B have different displacement sizes.

9. The method as claimed in claim 8, wherein when the sliding vane chamber pressure switching mode is used, the control valve device is operated in three steps by the motor to actuate the slider disposed thereon, so as to connect the first input port and the two output ports, or not to connect them, and simultaneously connect the second input port and the two output ports, or connect the second input port and the two output ports, thereby switching the pressures of the two output ports back and forth between three modes of a high pressure side and a high pressure side, a high pressure side and a low pressure side, and a low pressure side and a high pressure side, respectively, thereby realizing three-stage capacity switching control of the compressor;

or,

when the cylinder pressure switching mode is adopted, the control valve device drives the sliding block arranged on the control valve device to act in three steps through the motor, and the first input hole and the two output holes or any one of the two output holes are communicated; and the second input hole and any one of the two output holes are communicated at the same time or are not communicated, so that the pressures of the two output holes are switched back and forth between three modes of a low pressure side and a low pressure side, a low pressure side and a high pressure side, and a high pressure side and a low pressure side respectively, and the three-section capacity conversion control of the compressor is realized.

10. The method as set forth in claim 8, wherein three modes of said three-stage capacity switching control are alternately switched back and forth in sequence, or any one of the modes is eliminated and only the remaining two modes are directly switched back and forth.

11. The method as claimed in claim 8, wherein the capacity of the capacitor required for operation of the motor of the variable capacity type rotary compressor is two kinds of Rc2 and Rc3, wherein Rc3 < Rc2, and if the three-stage capacity controlled compressor is sequentially divided into three according to the operation capacity, the minimum operation capacity mode corresponds to the capacitor Rc3 of smaller capacity, the greater operation capacity mode corresponds to the capacitor Rc2 of larger capacity, and the maximum operation capacity mode corresponds to the superposition Rc3+ Rc2 of the capacitor of smaller capacity and the capacitor of larger capacity; or the capacity of the motor run capacitor is switched without changing the capacity mode of the compressor.

12. The method as set forth in claim 8, wherein the length of time of operation in each mode is arbitrarily controlled, so that the operation time in each mode can be adjusted to achieve stepless adjustment of the refrigerating capacity of the compressor or system per unit time.

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