Variable-capacity compression system, control method thereof, and air conditioner

Abstract

The present application relates to the technical field of compressor, more particularly, it relates to a variable displacement compression system, a control method thereof and an air conditioner, wherein the variable displacement compression system comprises a variable displacement gas passage, a pipeline control device and a variable displacement compressor, the variable displacement compressor has a unloadable cylinder; the variable displacement gas passage is used for connecting with the unloadable cylinder; the pipeline control device is used for controlling the variable displacement gas passage to introduce medium pressure on an intermediate pipeline or high pressure on an exhaust pipeline to the unloadable cylinder, and when the variable displacement gas passage introduces medium pressure or high pressure to the unloadable cylinder, the unloadable cylinder is in a load state, the variable displacement gas passage preferentially introduces medium pressure to the unloadable cylinder. According to the technical scheme of the present application, the power consumption and leakage of the variable displacement compressor in the high load operation mode can be reduced, the energy efficiency is improved, the force between the roller and the sliding sheet of the unloadable cylinder is reduced, and the abrasion is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressors, in particular to a variable displacement compression system, a control method thereof and an air conditioner. BACKGROUND

[0002] At present, compared with the traditional double-cylinder compressor, the rotor variable displacement compressor can unload one cylinder when the system is running at low load, thereby having obvious energy efficiency advantage over the traditional double-cylinder compressor.

[0003] The working volume adjustment method of the existing variable displacement compressor is basically as follows: by changing the pressure value at the tail of the sliding vane in the compression part, one of the two or more compression parts is unloaded, thereby changing the working volume of the compressor. For example, patent No. 201821760463.8 discloses a variable displacement mechanism, which can unload the cylinder and has a closed sliding vane tail cavity at the tail of the sliding vane. The sliding vane tail cavity can be selectively communicated with the high pressure of the compressor exhaust or the low pressure of the suction gas through an external pipeline. When the sliding vane tail cavity is communicated with the high pressure, the high pressure at the head of the pin overcomes the spring force, so that the pin is completely withdrawn into the pin hole. At this time, the compressor is in a double-cylinder high load operation mode. When the sliding vane tail cavity is communicated with the low pressure, the pin is pushed upward by the spring to protrude out of the pin hole, and the pin is inserted into the positioning hole on the sliding vane to lock the sliding vane in the sliding vane groove. At this time, the compressor is in a single-cylinder low load operation mode.

[0004] However, this structure has the following defects: when the compressor is running in double-cylinder mode, the sliding vane tail cavity of the unloadable cylinder is always communicated with the exhaust pressure of the compressor, so that the tail of the sliding vane maintains a stable high pressure, which causes a large pressure difference between the head and the tail of the sliding vane. Under high pressure difference conditions, on the one hand, the interaction force between the sliding vane and the roller of the unloadable cylinder increases, which leads to increased power consumption of the compressor, reduced energy efficiency, and easy wear between the sliding vane and the roller; on the other hand, since the sliding vane of the unloadable cylinder is isolated from the inside of the compressor shell, there is basically no lubricating oil between the sliding vane and the sliding vane groove. If the suction and exhaust pressure difference is large, the high pressure in the sliding vane tail cavity is likely to leak to the low pressure suction cavity through the gap between the sliding vane and the sliding vane groove, which leads to reduced refrigeration capacity of the compressor and reduced energy efficiency. SUMMARY

[0005] Therefore, the present application provides a variable displacement compression system, a control method thereof and an air conditioner, which mainly aims to solve the problems of increased power consumption, easy wear between the sliding vane and the roller, and refrigerant leakage caused by the unloadable cylinder being always communicated with the exhaust pressure in the high load operation mode of the existing variable displacement compressor.

[0006] To achieve the above-mentioned purpose, the present application mainly provides the following technical solutions:

[0007] In a first aspect, embodiments of the present application provide a variable capacity compression system, comprising a variable capacity scavenge line, a line control device and a variable capacity compressor, wherein the variable capacity compressor has an unloadable cylinder;

[0008] The variable capacity scavenge line is configured to be connected to the unloadable cylinder;

[0009] The line control device is configured to control the variable capacity scavenge line to introduce a medium pressure on an intermediate line or a high pressure on an exhaust line to the unloadable cylinder, and when both the medium pressure and the high pressure can make the unloadable cylinder in a loaded state, the variable capacity scavenge line preferentially introduces the medium pressure to the unloadable cylinder.

[0010] In some embodiments, the variable capacity compression system further comprises a detection device configured to detect the medium pressure P2, the high pressure P3 and a low pressure P1 on a suction line;

[0011] The line control device is configured to control the variable capacity scavenge line to introduce the medium pressure to the unloadable cylinder when P2 is greater than or equal to P0, and to control the variable capacity scavenge line to introduce the high pressure to the unloadable cylinder when P2 is less than P0;

[0012] P0=A(P1+P3)+Fm / (L*H), Fm is a friction force between a sliding vane and a sliding vane groove of the unloadable cylinder, Fm is in units of Newton, L is a thickness of the sliding vane of the unloadable cylinder, L is in units of meters, H is a height of the sliding vane of the unloadable cylinder, H is in units of meters, A is greater than or equal to 0.4 and less than or equal to 0.6, and P1, P3 and P0 are all in units of Pascals.

[0013] In some embodiments, the detection device comprises a first air pressure detection device, a second air pressure detection device and a third air pressure detection device;

[0014] The detection device detects the low pressure P1 through the first air pressure detection device, detects the medium pressure P2 through the second air pressure detection device, and detects the high pressure P3 through the third air pressure detection device.

[0015] In some embodiments, the line control device comprises a controller, a first electromagnetic valve and a second electromagnetic valve, one end of the first electromagnetic valve is connected to the variable capacity scavenge line, the other end is connected to the exhaust line, one end of the second electromagnetic valve is connected to the variable capacity scavenge line, the other end is connected to the intermediate line;

[0016] The line control device judges the size of P2 and P0 through the controller, and controls the second electromagnetic valve to be opened alone through the controller when P2 is greater than or equal to P0, and controls the first electromagnetic valve to be opened alone when P2 is less than P0.

[0017] In some embodiments, the intermediate pipeline has a flash evaporator, and the intermediate pipeline delivers the medium pressure to the variable-volume scavenge pipeline through the flash evaporator.

[0018] In some embodiments, the pipeline control device is further configured to control the variable-volume scavenge pipeline to introduce the low pressure on the suction pipeline to the unloadable cylinder; wherein the pipeline control device comprises a switch valve, one end of the switch valve being connected with the variable-volume scavenge pipeline, and the other end of the switch valve being connected with the suction pipeline.

[0019] In some embodiments, the unloadable cylinder comprises a cylinder and a sliding vane, the sliding vane being provided with a positioning hole, a sliding vane groove and a sliding vane tail cavity, the sliding vane tail cavity being in communication with the sliding vane groove, the sliding vane being slidably arranged in the sliding vane groove, and the unloadable cylinder being connected with the variable-volume scavenge pipeline through the sliding vane tail cavity.

[0020] The variable-volume compressor further comprises a pin, an elastic member and a flange, the flange being used to cover one side of the cylinder, the flange being provided with a pin hole, the pin hole being in communication with the sliding vane tail cavity, and the pin being telescopically arranged in the pin hole; wherein when the variable-volume scavenge pipeline introduces the medium pressure or the high pressure into the unloadable cylinder, the pin is retracted into the pin hole under the pushing of the tail cavity pressure; when the variable-volume scavenge pipeline introduces the low pressure on the suction pipeline into the unloadable cylinder, the pin is extended out of the pin hole under the pushing of the elastic member and is inserted into the positioning hole.

[0021] In a second aspect, embodiments of the present application further provide a control method of any of the above variable-volume compression systems, which comprises:

[0022] controlling the variable-volume scavenge pipeline to introduce the medium pressure on the intermediate pipeline or the high pressure on the exhaust pipeline to the unloadable cylinder of the variable-volume compressor, and when both the medium pressure and the high pressure introduced by the variable-volume scavenge pipeline to the unloadable cylinder can make the unloadable cylinder in a loaded state, controlling the variable-volume scavenge pipeline to preferentially introduce the medium pressure to the unloadable cylinder.

[0023] In some embodiments, the control method of the variable-volume compression system further comprises:

[0024] detecting the medium pressure P2, the high pressure P3 and the low pressure P1 on the suction pipeline;

[0025] controlling the variable-volume scavenge pipeline to introduce the medium pressure to the unloadable cylinder when P2 is greater than or equal to P0, and controlling the variable-volume scavenge pipeline to introduce the high pressure to the unloadable cylinder when P2 is less than P0;

[0026] P0=A(P1+P3)+Fm / (L*H), Fm is the friction between the slide and the slide groove of the unloadable cylinder, the unit of Fm is Newton, L is the thickness of the slide of the unloadable cylinder, the unit of L is meter, H is the height of the slide of the unloadable cylinder, the unit of H is meter, A is greater than or equal to 0.4 and less than or equal to 0.6, the units of P1, P3 and P0 are all Pascal.

[0027] In a third aspect, embodiments of the present application also provide an air conditioner, which can include any of the above-mentioned variable displacement compression systems.

[0028] By the above technical solutions, the variable displacement compression system, the control method thereof and the air conditioner provided by the present application have at least the following beneficial effects:

[0029] In the technical solutions provided by the present application, when the medium pressure or the high pressure introduced into the unloadable cylinder can make the unloadable cylinder in the loaded state, since the medium pressure is introduced into the unloadable cylinder preferentially, compared with the prior art in which the high pressure is always introduced into the unloadable cylinder, the relative force between the slide and the roller of the unloadable cylinder can be reduced, so that the power consumption of the variable displacement compressor is reduced, the energy efficiency is improved, and the wear between the slide and the roller can also be reduced. In addition, by introducing the medium pressure into the unloadable cylinder, the pressure difference between the tail part and the head part of the slide is reduced, so that the leakage of the refrigerant in the tail cavity of the slide into the suction cavity can be reduced, and the energy efficiency of the compressor is improved.

[0030] The above description is only a summary of the technical solutions of the present application. In order to make the technical solutions of the present application clearer and to enable the content of the present application to be implemented, the preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and other accompanying drawings can also be obtained by those skilled in the art without creative labor on the basis of the structure shown in the accompanying drawings.

[0032] Figure 1 is a structural schematic diagram of a variable displacement compression system provided by an embodiment of the present application;

[0033] Figure 2 is a structural schematic diagram of a pump body assembly of a variable displacement compressor;

[0034] Figure 3 is a position schematic diagram of a pin and a slide when the unloadable cylinder is in the loaded state;

[0035] Figure 4 This is a schematic diagram showing the positions of the pin and the slide when the unloadable cylinder is in the unloading state.

[0036] Figure 5 This is a schematic diagram of the forces acting on the sliding vane of a detachable cylinder.

[0037] Figure 6 This is a comparison chart of the energy efficiency of the variable capacity compressor of the present invention compared with existing variable capacity compressors under high load operation.

[0038] Reference numerals: 1. Exhaust pipe; 2. Condenser; 3. First throttling device; 4. Flash evaporator; 5. Second throttling device; 6. Evaporator; 7. Suction pipe; 8. Liquid distributor; 10. Variable capacity compressor; 11. Motor assembly; 12. Switch valve; 13. Second solenoid valve; 14. First solenoid valve; 15. Variable capacity vent pipe; 16. Crankshaft; 17. Upper flange; 18. Another cylinder; 19. Another roller; 20. Another vane; 21. Spring; 22. Baffle; 23. Cylinder; 24. Roller; 25. Vane; 26. Lower flange; 27. Pin; 28. Elastic element; 29. ​​Cover plate; 30. Pin hole; 31. Vane tail cavity; 32. Positioning hole; 33. First pressure detection device; 34. Second pressure detection device; 35. Third pressure detection device. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0041] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope required by the present application.

[0042] As shown in Figure 1 An embodiment of the present application proposes a variable displacement compressor system, which comprises a variable displacement compressor 10.

[0043] The variable displacement compressor 10 has an unloadable cylinder and another cylinder. As shown in Figure 2 The unloadable cylinder and the other cylinder are separated by a partition plate 22. The unloadable cylinder comprises a cylinder body 23, a roller 24 and a sliding vane 25. The unloadable cylinder has two states of a loaded state and an unloaded state, the unloadable cylinder is in a working mode in the loaded state, and the unloadable cylinder is in an unloaded mode in the unloaded state. The roller 24 is installed in the cylinder body 23, and the roller 24 is sleeved on one eccentric part of the crankshaft 16. The sliding vane 25 is slidably installed in the sliding vane groove of the cylinder body 23. The tail of the sliding vane 25 is a closed cavity, which is a sliding vane tail cavity 31.

[0044] As shown in Figure 2 The other cylinder comprises another cylinder body 18, another roller 19, another sliding vane 20 and a spring 21. The other sliding vane 20 is slidably installed in the sliding vane groove of the other cylinder body 18. The other roller 19 is installed in the other cylinder body 18, and the other roller 19 is sleeved on the other eccentric part of the crankshaft 16. The spring 21 is arranged at the tail of the other sliding vane 20. The side of the other cylinder body 18 away from the partition plate 22 is provided with a flange, which can be the upper flange 17. When the motor assembly 11 operates, the motor assembly 11 drives the crankshaft 16, the roller 24 and the other roller 19 to move. Since the other cylinder contains the spring 21, the other cylinder first starts to compress the refrigerant and can establish a certain suction and discharge pressure difference. At this time, the working mode of the variable displacement compressor 10 is switched according to the system load demand.

[0045] The aforementioned variable displacement compressor 10 has two operating states of a first operating mode and a second operating mode. The first operating mode can also be referred to as a high load operating mode, in which the variable displacement compressor 10 is double-cylinder or multi-cylinder operated. The second operating mode is also referred to as a low load operating mode, in which the variable displacement compressor 10 is single-cylinder operated. In one specific application example, the variable displacement compressor 10 is a double-cylinder rotary compressor, which has an unloadable cylinder and an ununloadable cylinder. The unloadable cylinder has an unloaded state and a loaded state, and the ununloadable cylinder only has a loaded state. The loaded state can also be understood as a working state. In the high load operating mode, the unloadable cylinder of the variable displacement compressor 10 is in the loaded state, and the variable displacement compressor 10 is double-cylinder operated. In the low load operating mode, the unloadable cylinder of the variable displacement compressor 10 is in the unloaded state, and the variable displacement compressor 10 is single-cylinder operated.

[0046] As shown in Figure 1 The aforementioned variable displacement compression system further comprises a variable displacement scavenge line 15 and a line control device. The variable displacement scavenge line 15 is used to connect with the unloadable cylinder. Specifically, the aforementioned unloadable cylinder is connected with the variable displacement scavenge line 15 through the slide tail cavity 31. In the first operating mode of the variable displacement compressor 10, the line control device is used to control the variable displacement scavenge line 15 to introduce medium pressure on the intermediate line or high pressure on the exhaust line 1 to the unloadable cylinder. When both the introduction of medium pressure and the introduction of high pressure to the unloadable cylinder by the variable displacement scavenge line 15 can make the unloadable cylinder in the loaded state, the variable displacement scavenge line 15 preferentially introduces medium pressure to the unloadable cylinder.

[0047] As shown in Figure 1 The aforementioned variable displacement compression system further comprises an evaporator 6, a condenser 2 and a throttling device. The variable displacement compressor 10, the condenser 2, the throttling device and the evaporator 6 form a refrigerant circuit. The refrigerant circuit has a suction line 7, an exhaust line 1 and an intermediate line. The suction line 7 is connected with the suction port of the variable displacement compressor 10, and is used to send the refrigerant flowing out of the evaporator 6 into the variable displacement compressor 10. The suction line 7 can also be provided with a distributor 8. The exhaust line 1 is connected with the exhaust port of the variable displacement compressor 10, and is used to send the high-pressure refrigerant compressed by the variable displacement compressor 10 into the condenser 2. The intermediate line is other lines on the refrigerant circuit except the suction line 7 and the exhaust line 1. For example, the intermediate line can be a charge line, or the intermediate line is a line between the condenser 2 and the evaporator 6. The refrigerant pressure in the exhaust line 1 is greater than the refrigerant pressure in the intermediate line, and the refrigerant pressure in the intermediate line is greater than the refrigerant pressure in the suction line 7.

[0048] The intermediate pipeline may include a flash evaporator 4, through which medium pressure is supplied to the variable-capacity venting pipeline 15. The flash evaporator 4 allows the refrigerant to undergo flash evaporation, transforming the two-phase refrigerant into saturated gaseous and saturated liquid components. The saturated gaseous refrigerant is then introduced into the unloading cylinder, while the saturated liquid refrigerant can enter the evaporator 6 through throttling. The throttling device may include a first throttling device 3 and a second throttling device 5, with the flash evaporator 4 positioned on the intermediate pipeline between the first throttling device 3 and the second throttling device 5.

[0049] In the above example, when both medium and high pressure can be introduced into the unloadable cylinder to put it under load, the present invention can reduce the relative force between the vane 25 and the roller 24 of the unloadable cylinder by preferentially introducing medium pressure into the unloadable cylinder, compared with the prior art which always introduces high pressure into the unloadable cylinder. This reduces the power consumption of the variable capacity compressor 10, improves energy efficiency, and also reduces wear between the vane 25 and the roller 24. In addition, by introducing medium pressure into the unloadable cylinder, the pressure difference between the tail and head of the vane 25 is reduced, thereby reducing the leakage of refrigerant from the tail cavity 31 of the vane into the suction cavity and improving the energy efficiency of the compressor.

[0050] To achieve the function of the aforementioned pipeline control device, when the variable-capacity venting pipeline 15 can be used to introduce either medium or high pressure into the unloadable cylinder to put the unloadable cylinder under load, the pipeline control device controls the variable-capacity venting pipeline 15 to preferentially introduce medium pressure into the unloadable cylinder. The present invention also provides the following embodiment: the aforementioned variable-capacity compression system may further include a detection device for detecting the medium pressure P2 on the intermediate pipeline, the high pressure P3 on the exhaust pipeline 1, and the low pressure P1 on the intake pipeline 7. In a specific application example, such as... Figure 1 As shown, the detection device may include a first air pressure detection device 33, a second air pressure detection device 34, and a third air pressure detection device 35. The detection device detects low pressure P1 through the first air pressure detection device 33, medium pressure P2 through the second air pressure detection device 34, and high pressure P3 through the third air pressure detection device 35. The first air pressure detection device 33, the second air pressure detection device 34, and the third air pressure detection device 35 can all be commercially available components, and their specific structures are existing technology and will not be described in detail here.

[0051] The variable displacement compressor 10 in the first operating mode, i.e. the high load operating mode, the pipeline control device is used to control the variable displacement port 15 to the unloadable cylinder to introduce the medium pressure, and to control the variable displacement port 15 to the unloadable cylinder to introduce the high pressure when P2 is less than P0. Wherein, P0=A(P1+P3)+Fm / LH, Fm is the friction between the slide 25 and the slide groove of the unloadable cylinder, the unit of Fm is Newton, L is the thickness of the slide 25 of the unloadable cylinder, the unit of L is meter, H is the height of the slide 25 of the unloadable cylinder, the unit of H is meter, the units of P1, P3 and P0 are all Pascal. A is greater than or equal to 0.4 and less than or equal to 0.6. Preferably, A=0.5.

[0052] Wherein, when P2 is greater than or equal to P0, the medium pressure on the intermediate pipeline can make the slide 25 of the unloadable cylinder follow the reciprocating motion of the roller 24 at all times after being introduced into the unloadable cylinder, in other words, the medium pressure at this time can ensure that the unloadable cylinder is in a load state, ensuring that the variable displacement compressor 10 can operate stably in the first operating mode, i.e. the high load operating mode. When P2 is less than P0, the medium pressure on the intermediate pipeline cannot ensure that the slide 25 of the unloadable cylinder can follow the reciprocating motion of the roller 24 at all times after being introduced into the unloadable cylinder, in other words, the medium pressure at this time cannot ensure that the unloadable cylinder is in a load state.

[0053] In the above example, by detecting the medium pressure P2 on the intermediate pipeline, the high pressure P3 on the exhaust pipeline 1 and the low pressure P1 on the suction pipeline 7, then calculating the size of P0 according to the formula, then comparing the size of P0 and P2, if P2 is greater than or equal to P0, the medium pressure is selected to be introduced, if P2 is less than P0, the high pressure is selected to be introduced, so as to realize the function of the pipeline control device, so that the pipeline control device can control the variable displacement port 15 to preferentially introduce the medium pressure to the unloadable cylinder when the unloadable cylinder is in a load state.

[0054] Wherein, when the medium pressure P2 is greater than or equal to P0, the medium pressure on the intermediate pipeline can make the slide 25 of the unloadable cylinder follow the reciprocating motion of the roller 24 at all times after being introduced into the unloadable cylinder, in other words, the medium pressure at this time can ensure that the unloadable cylinder is in a load state. The following is a specific description.

[0055] Figure 5The force state of the slide 25 of the unloadable cylinder of the rotor type double cylinder compressor in the first operation mode, i.e. the high load operation mode, is shown. The height of the slide 25 of the unloadable cylinder is H, and the thickness is L. The size of the low pressure on the suction pipeline 7 is P1, the size of the high pressure on the exhaust pipeline 1 is P3, and the size of the medium pressure on the intermediate pipeline is P2. The pressure in the suction chamber of the unloadable cylinder is Pa, the pressure in the compression chamber is Pb, and the pressure in the slide tail chamber 31, i.e. the slide tail chamber 31, is Pc. When the variable displacement compressor 10 is operated in the double cylinder mode, the slide 25 follows the roller 24 to make reciprocating motion, and the slide 25 is subjected to the forces F1, F2, F3, Fm and Fn in the direction of motion. Among them, F1 is the gas force of the suction chamber acting on the head of the slide 25, F2 is the gas force of the compression chamber acting on the head of the slide 25, F3 is the gas force of the tail chamber 31 acting on the tail of the slide 25, Fm is the friction force between the slide 25 and the slide groove, and Fn is the inertial force generated by the motion of the slide 25, and Fn can be neglected due to the light weight of the slide 25.

[0056] If the slide 25 can always follow the motion of the roller 24, the following condition must be met: F3-(F1+F2)-Fm≧0.

[0057] It can be approximately considered that the proportion of the gas in the suction chamber and the exhaust chamber acting on the head of the slide 25 is A, and preferably A is 0.5. That is, the gas in the suction chamber and the exhaust chamber acts on half of the head of the slide 25, so it only needs to meet: Pc*LH-(APa*LH+APb*LH)-Fm≧0 (Formula I).

[0058] Further, the compressor suction chamber pressure Pa is equal to the low pressure P1 on the suction pipeline 7, and the compression chamber pressure Pb gradually increases from P1 to P3 with the rotation of the compressor, and then the high pressure gas is discharged from the cylinder body 23 to the inside of the compressor shell, so Pb≦P3.

[0059] Therefore, formula I can be converted to Pc≧A(P1+P3)+Fm / LH; and the size of Fm is greatly related to the gap between the slide 25 and the slide groove, and the smaller the gap between the slide 25 and the slide groove, the larger Fm is. The value of Fm is generally 5-55N.

[0060] Based on the above derivation, when the pressure Pc ≥ A(P1+P3) + Fm / LH in the sliding vane tail chamber 31 of the unloading cylinder 23, the sliding vane 25 of the unloading cylinder will reciprocate with the roller 24, thus placing the unloading cylinder under load. Therefore, when the intermediate pressure P2 ≥ A(P1+P3) + Fm / LH, i.e., P2 ≥ P0, is detected on the intermediate pipeline, introducing the intermediate pressure P2 into the unloading cylinder will place it under load. When the medium pressure P2 ≥ P0, both medium pressure P2 and high pressure P3 can make the unloadable cylinder operate under load. Since medium pressure P2 is less than high pressure P3, medium pressure P2 is introduced to make the unloadable cylinder operate under load. On the one hand, this ensures that the vane 25 can always follow the roller 24 in reciprocating motion, ensuring that the variable displacement compressor 10 can operate stably in dual-cylinder mode. On the other hand, it reduces the relative force between the vane 25 and the roller 24, reducing the power consumption of the variable displacement compressor 10. Furthermore, since the pressure difference between the tail and head of the vane 25 is reduced, the leakage from the tail sealing cavity of the vane 25, i.e., the vane tail cavity 31, to the suction cavity is reduced, resulting in a certain increase in cooling capacity.

[0061] Figure 6 A comparison graph showing the energy efficiency of a variable capacity compressor 10 of the present invention compared to a conventional variable capacity compressor in a high-load operation mode is provided. In the graph, the solid line represents the variable capacity compressor 10 of the present invention, and the dashed line represents a conventional variable capacity compressor. Figure 6 As can be seen from the figure, as the pressure difference between the compressor's suction and discharge increases, when the pressure difference between the compressor's suction and discharge is greater than or equal to ΔP, the intermediate pressure P2 satisfies P2≧A(P1+P2)+Fm / LH. At this time, the intermediate pressure P2 is introduced into the vane tail cavity 31 of the unloadable cylinder of the present invention. Compared with the existing variable capacity compressor 10, which always introduces high pressure P3 into the vane tail cavity 31 of the unloadable cylinder, it can be seen from the figure that when the pressure difference between the compressor's suction and discharge is greater than or equal to ΔP, the introduction of intermediate pressure into the vane tail cavity 31 of the variable capacity compressor 10 of the present invention increases its cooling capacity and reduces its power consumption. As a result, the energy efficiency COP of the variable capacity compressor of the present invention is significantly better than that of the existing variable capacity compressor.

[0062] To achieve the aforementioned function of the pipeline control device, the device can control the variable-capacity venting pipeline 15 to introduce medium pressure into the unloadable cylinder when P2 is greater than or equal to P0, and control the variable-capacity venting pipeline 15 to introduce high pressure into the unloadable cylinder when P2 is less than P0. Figure 1As shown, the pipeline control device can include a controller, a first electromagnetic valve 14 and a second electromagnetic valve 13. One end of the first electromagnetic valve 14 is connected with the variable-volume venting pipeline 15, and the other end is connected with the exhaust pipeline 1. One end of the second electromagnetic valve 13 is connected with the variable-volume venting pipeline 15, and the other end is connected with the intermediate pipeline. The controller can be a microprocessor or a PLC, etc. The pipeline control device judges the size of P2 and P0 through the controller, and controls the second electromagnetic valve 13 to open alone when P2 is greater than or equal to P0, and controls the first electromagnetic valve 14 to open alone when P2 is less than P0.

[0063] In the above example, when the controller controls the second electromagnetic valve 13 to open alone, the variable-volume venting pipeline 15 is only communicated with the intermediate pipeline, so that the medium pressure on the intermediate pipeline can be introduced into the unloadable cylinder. When the controller controls the first electromagnetic valve 14 to open alone, the variable-volume venting pipeline 15 is only communicated with the exhaust pipeline 1, so that the high pressure on the exhaust pipeline 1 can be introduced into the unloadable cylinder.

[0064] The foregoing variable-volume compressor 10 is in the second operating mode, i.e. the low load operating mode, and the pipeline control device is further used to control the variable-volume venting pipeline 15 to introduce the low pressure on the suction pipeline 7 into the unloadable cylinder, so that the unloadable cylinder is in the unloaded state. In this way, the pipeline control device can switch the unloadable cylinder between the loaded state and the unloaded state by controlling the variable-volume venting pipeline 15 to introduce the low pressure, the medium pressure or the high pressure into the unloadable cylinder, so as to realize the variable-volume control of the compressor.

[0065] As shown in Figure 1 The foregoing pipeline control device can further include a switch valve 12, one end of which is connected with the variable-volume venting pipeline 15, and the other end is connected with the suction pipeline 7. The switch valve 12 can be an electromagnetic valve, so as to facilitate automatic control. When the variable-volume compressor 10 is in the second operating mode, i.e. the low load operating mode, the foregoing controller controls the switch valve 12 to open alone, so that the low pressure on the suction pipeline 7 can be automatically introduced into the unloadable cylinder.

[0066] As shown in Figure 3 and Figure 4As shown, the foregoing unloadable cylinder includes a cylinder body 23 and a sliding vane 25, the sliding vane 25 is provided with a positioning hole 32, a sliding vane groove and a sliding vane tail cavity 31. The sliding vane tail cavity 31 is in communication with the sliding vane groove, and the sliding vane tail cavity 31 is a sealed cavity. The sliding vane 25 is slidably arranged in the sliding vane groove. The unloadable cylinder is connected with the foregoing variable volume venting pipeline 15 through the sliding vane tail cavity 31. The variable volume compressor 10 further includes a pin 27, an elastic member 28 and a flange. The flange can be a lower flange 26. The side of the lower flange 26 away from the cylinder body 23 is further provided with a cover plate 29. The flange is used to cover one side of the cylinder body 23, and the flange is provided with a pin hole 30 in communication with the sliding vane tail cavity 31. The pin 27 is telescopically arranged in the pin hole 30. When the variable volume venting pipeline 15 introduces medium pressure or high pressure into the unloadable cylinder, the pin 27 is retracted into the pin hole 30 under the pushing of the pressure in the tail cavity 31; when the variable volume venting pipeline 15 introduces low pressure on the suction pipeline 7 into the unloadable cylinder, the pin 27 is extended out of the pin hole 30 under the pushing of the elastic member 28, and is inserted into the positioning hole 32.

[0067] In the above example, as Figure 3 shown, the tail of the pin 27 is always low pressure, at this time the sliding vane tail cavity 31 is high pressure or medium pressure, the pressure of the head of the pin 27 overcomes the force of the spring 21, and the pin 27 is completely retracted into the pin hole, at this time the variable volume compressor 10 is in the first operating mode, i.e. the double cylinder operating mode. As Figure 4 shown, the tail and the head of the pin 27 are both low pressure, the head of the pin 27 is pushed upward by the force of the spring 21, and cooperates with the sliding vane 25 of the unloadable cylinder to lock the sliding vane 25, at this time the variable volume compressor 10 is in the second operating mode, i.e. the single cylinder operating mode.

[0068] The embodiments of the present application also provide a control method of any one of the foregoing variable volume compression systems, which comprises:

[0069] controlling the variable volume venting pipeline 15 to introduce medium pressure on the intermediate pipeline or high pressure on the exhaust pipeline 1 into the unloadable cylinder of the variable volume compressor 10, and when the unloadable cylinder is in a loaded state under the introduction of medium pressure or high pressure into the unloadable cylinder through the variable volume venting pipeline 15, controlling the variable volume venting pipeline 15 to preferentially introduce medium pressure into the unloadable cylinder.

[0070] When the unloadable cylinder is in the load state by introducing the medium pressure or the high pressure into the unloadable cylinder, the relative force between the slide 25 and the roller 24 of the unloadable cylinder can be reduced by introducing the medium pressure into the unloadable cylinder preferentially, compared with the prior art in which the high pressure is always introduced into the unloadable cylinder, so that the power consumption of the variable displacement compressor 10 is reduced, the energy efficiency is improved, and the abrasion between the slide 25 and the roller 24 is reduced. In addition, the pressure difference between the tail and the head of the slide 25 is reduced by introducing the medium pressure into the unloadable cylinder, so that the leakage of the refrigerant in the slide tail cavity 31 into the suction cavity is reduced, and the energy efficiency of the compressor is improved.

[0071] The control method of the variable displacement compression system further comprises the following steps: step S1, detecting the medium pressure P2 on the intermediate pipeline, the high pressure P3 on the exhaust pipeline 1 and the low pressure P1 on the suction pipeline 7. Step S2, controlling the variable displacement vent pipeline 15 to introduce the medium pressure into the unloadable cylinder when P2 is greater than or equal to P0, and controlling the variable displacement vent pipeline 15 to introduce the high pressure into the unloadable cylinder when P2 is less than P0. Wherein, P0=A(P1+P3)+Fm / (L*H), Fm is the friction force between the slide 25 and the slide groove of the unloadable cylinder, the unit of Fm is Newton, L is the thickness of the slide 25 of the unloadable cylinder, the unit of L is meter, H is the height of the slide 25 of the unloadable cylinder, the unit of H is meter, A is greater than or equal to 0.4 and less than or equal to 0.6, and the units of P1, P3 and P0 are all Pascal.

[0072] In the above example, the medium pressure P2 on the intermediate pipeline, the high pressure P3 on the exhaust pipeline 1 and the low pressure P1 on the suction pipeline 7 are detected, then the size of P0 is calculated according to the formula, and then the sizes of P0 and P2 are compared. If P2 is greater than or equal to P0, the medium pressure is selected to be introduced, and if P2 is less than P0, the high pressure is selected to be introduced. In this way, the automatic control components such as the processor and the electromagnetic valve are matched, so that the pressure of the refrigerant introduced into the variable displacement vent pipeline 15 can be automatically selected and controlled.

[0073] The embodiments of the present application also provide an air conditioner which can comprise any one of the variable displacement compression systems described above. Due to the adoption of the variable displacement compression system described above, the relative force between the slide 25 and the roller 24 of the unloadable cylinder can be reduced, so that the power consumption of the variable displacement compressor 10 is reduced, the energy efficiency is improved, and the abrasion between the slide 25 and the roller 24 is reduced. In addition, the pressure difference between the tail and the head of the slide 25 is reduced by introducing the medium pressure into the unloadable cylinder, so that the leakage of the refrigerant in the slide tail cavity 31 into the suction cavity is reduced, and the energy efficiency of the compressor is improved.

[0074] The working principle and the preferred embodiments of the present application will be introduced below.

[0075] The present application provides a variable displacement compressor system, which comprises a variable displacement compressor 10, the variable displacement compressor 10 comprising an unloadable cylinder and another cylinder, the two compression parts being separated by a partition 22, and the main features are as follows:

[0076] 1. The tail of the slide 25 of the unloadable cylinder is a slide tail cavity 31, which is a sealed cavity structure, and the slide tail cavity 31 can be selectively communicated with the suction pressure, the discharge pressure or the intermediate pressure, so that the unloadable cylinder can be switched between the load state and the unload state. Among them, the unloadable cylinder is in working mode in the load state, and the unloadable cylinder is in unload mode in the unload state.

[0077] 2. The tail of the slide 25 of the other cylinder is provided with a spring 21, the other cylinder is always running and cannot be unloaded, and is used to establish a certain suction and discharge pressure difference when the compressor starts.

[0078] 3. The slide tail cavity 31 of the unloadable cylinder is connected with a variable displacement vent pipe 15, the variable displacement vent pipe 15 is connected with a flash evaporator 4 through a second electromagnetic valve 13, connected with a discharge pipe 1 through a first electromagnetic valve 14, and connected with a suction pipe 7 through a switch valve 12, wherein the switch valve 12 can be a third electromagnetic valve. When the variable displacement compressor 10 is running, only one electromagnetic valve is in the open state, so as to control the slide tail cavity 31 to be communicated with the suction pressure, the discharge pressure or the intermediate pressure.

[0079] 4. When the variable displacement compressor 10 is single-cylinder running, the switch valve 12 is opened, the slide tail cavity 31 of the unloadable cylinder is communicated with the suction pressure, and the slide 25 of the unloadable cylinder is locked with the pin 27. When the variable displacement compressor 10 is double-cylinder running, one of the first electromagnetic valve 14 and the second electromagnetic valve 13 is opened, the slide tail cavity 31 of the unloadable cylinder is communicated with the intermediate pressure or the discharge pressure, and the slide 25 of the unloadable cylinder always follows the reciprocating motion of the roller 24.

[0080] 5. When the variable displacement compressor 10 is double-cylinder running, according to the state of the suction pressure P1, the intermediate pressure P2 and the discharge pressure P3, if P2≧0.5(P1+P3)+Fm / LH is satisfied, the second electromagnetic valve 13 is opened, and the slide tail cavity 31 is communicated with the intermediate pressure; if P2≧0.5(P1+P3)+Fm / LH is not satisfied, the first electromagnetic valve 14 is opened, and the slide tail cavity 31 is communicated with the discharge pressure.

[0081] 6. The above-mentioned variable displacement compressor 10 can not only be a double-cylinder variable displacement compressor, but also a three-cylinder or multi-cylinder variable displacement compressor. The variable displacement compressor 10 of the present application is not limited to vertical compressors, but can also be used in horizontal compressors and the like.

[0082] The above merely describes the preferred embodiments of the present application, and is not intended to limit the patent scope of the present application. Any equivalent structural changes made according to the content of the present application specification and drawings, or direct / indirect application in other related technical fields, are included in the patent protection scope of the present application.

Claims

1. A variable capacitance compression system, characterized by, The variable volume venting pipeline (15), the pipeline control device and the variable volume compressor (10) are provided, and the variable volume compressor (10) has an unloadable cylinder; The variable volume venting pipeline (15) is used for being connected with the unloadable cylinder; The pipeline control device is used for controlling the variable volume venting pipeline (15) to introduce the medium pressure on the intermediate pipeline or the high pressure on the exhaust pipeline (1) into the unloadable cylinder, and when the unloadable cylinder is in a load state under the introduction of the medium pressure or the high pressure by the variable volume venting pipeline (15), the variable volume venting pipeline (15) preferentially introduces the medium pressure into the unloadable cylinder; The variable volume compression system further comprises a detection device, and the detection device is used for detecting the medium pressure P2, the high pressure P3 and the low pressure P1 on the suction pipeline (7); The pipeline control device is used for controlling the variable volume venting pipeline (15) to introduce the medium pressure into the unloadable cylinder when P2 is greater than or equal to P0, and controlling the variable volume venting pipeline (15) to introduce the high pressure into the unloadable cylinder when P2 is less than P0; Wherein, P0=A(P1+P3)+Fm / (L*H), Fm is the friction force between the sliding vane (25) and the sliding vane groove of the unloadable cylinder, the unit of Fm is Newton, L is the thickness of the sliding vane (25) of the unloadable cylinder, the unit of L is meter, H is the height of the sliding vane (25) of the unloadable cylinder, the unit of H is meter, A is greater than or equal to 0.4 and less than or equal to 0.6, and the units of P1, P3 and P0 are all Pascal.

2. The variable volume compression system according to claim 1, wherein The detection device comprises a first air pressure detection device (33), a second air pressure detection device (34) and a third air pressure detection device (35); The detection device detects the low pressure P1 through the first air pressure detection device (33), detects the medium pressure P2 through the second air pressure detection device (34), and detects the high pressure P3 through the third air pressure detection device (35).

3. The variable volume compression system according to claim 1 or 2, wherein The pipeline control device comprises a controller, a first electromagnetic valve (14) and a second electromagnetic valve (13), one end of the first electromagnetic valve (14) is connected with the variable volume venting pipeline (15), and the other end is connected with the exhaust pipeline (1); one end of the second electromagnetic valve (13) is connected with the variable volume venting pipeline (15), and the other end is connected with the intermediate pipeline; The pipeline control device judges the size of P2 and P0 through the controller, and controls the second electromagnetic valve (13) to be opened alone when P2 is greater than or equal to P0 through the controller, and controls the first electromagnetic valve (14) to be opened alone when P2 is less than P0.

4. The variable volume compression system according to any one of claims 1 to 2, wherein The intermediate pipeline has a flash evaporator (4), and the intermediate pipeline delivers the medium pressure to the variable volume venting pipeline (15) through the flash evaporator (4).

5. The variable volume compression system according to any one of claims 1 to 2, wherein The pipeline control device is also used for controlling the variable volume venting pipeline (15) to introduce low pressure on the suction pipeline (7) to the unloadable cylinder; wherein the pipeline control device comprises a switch valve (12), one end of the switch valve (12) is connected with the variable volume venting pipeline (15), and the other end is connected with the suction pipeline (7).

6. The variable volume compression system according to claim 5, wherein, The unloadable cylinder comprises a cylinder body (23) and a sliding vane (25), the sliding vane (25) is provided with a positioning hole (32), a sliding vane groove and a sliding vane tail cavity (31), the sliding vane tail cavity (31) is communicated with the sliding vane groove, the sliding vane (25) is slidably arranged in the sliding vane groove, and the unloadable cylinder is connected with the variable volume venting pipeline (15) through the sliding vane tail cavity (31); The variable volume compressor further comprises a pin (27), an elastic member (28) and a flange, the flange is used for covering one side of the cylinder body (23), the flange is provided with a pin hole (30), the pin hole (30) is communicated with the sliding vane tail cavity (31), and the pin (27) is telescopically arranged in the pin hole (30); wherein when the variable volume venting pipeline (15) introduces the medium pressure or the high pressure into the unloadable cylinder, the pin (27) is pushed into the pin hole (30) under the tail cavity (31) pressure; when the variable volume venting pipeline (15) introduces low pressure on the suction pipeline (7) into the unloadable cylinder, the pin (27) is pushed out of the pin hole (30) under the elastic member (28) and is inserted into the positioning hole (32).

7. A method of controlling the variable capacitance compression system according to any one of claims 1 to 6, characterized by, Comprise: Controlling the variable volume venting pipeline (15) to introduce medium pressure on the intermediate pipeline or high pressure on the exhaust pipeline (1) to the unloadable cylinder of the variable volume compressor (10), and when the medium pressure or the high pressure introduced by the variable volume venting pipeline (15) into the unloadable cylinder can make the unloadable cylinder in a loaded state, controlling the variable volume venting pipeline (15) to preferentially introduce the medium pressure into the unloadable cylinder.

8. The control method according to claim 7, characterized by, Also comprise: Detecting the medium pressure P2, the high pressure P3 and the low pressure P1 on the suction pipeline (7); Controlling the variable volume venting pipeline (15) to introduce the medium pressure into the unloadable cylinder when P2 is greater than or equal to P0, and controlling the variable volume venting pipeline (15) to introduce the high pressure into the unloadable cylinder when P2 is less than P0; Wherein, P0=A(P1+P3)+Fm / (L*H), Fm is the friction force between the sliding vane (25) and the sliding vane groove of the unloadable cylinder, the unit of Fm is Newton, L is the thickness of the sliding vane (25) of the unloadable cylinder, the unit of L is meter, H is the height of the sliding vane (25) of the unloadable cylinder, the unit of H is meter, A is greater than or equal to 0.4 and less than or equal to 0.6, and the units of P1, P3 and P0 are all Pascal.

9. An air conditioner characterized by comprising: The variable volume compression system according to any one of claims 1 to 6. The variable volume compression system according to any one of claims 1 to 6.

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