CN115962117A - Variable-volume piston compressor, control method and refrigerator - Google Patents

Abstract

The invention provides a variable-capacity piston compressor, a control method and a refrigerator, wherein the variable-capacity piston compressor comprises: the piston is arranged in the cylinder and can reciprocate to form a compression cavity in the cylinder, the cylinder seat is connected with the cylinder, and a valve component is arranged on the cylinder seat; when the exhaust pressure of the cylinder is greater than the suction pressure and the difference value between the exhaust pressure and the suction pressure is greater than the preset force, the valve assembly can control the air supply pipe to be communicated with the compression cavity so as to supply air and increase enthalpy to the compression cavity; when the exhaust pressure is greater than the suction pressure and the difference value between the exhaust pressure and the suction pressure is less than or equal to the preset force, the valve assembly can control the air supplementing pipe not to be communicated with the compression cavity. According to the invention, the capacity-variable function can be realized, whether air is supplied or not can be automatically controlled according to the working condition, the low-working-condition and low-refrigerating-capacity operation is realized, and the energy consumption is reduced; and the high-pressure air compressor runs at a large refrigerating capacity under a high working condition, meets the refrigerating requirement and improves the general performance of the compressor.

Description

Variable-volume piston compressor, control method and refrigerator

Technical Field

The invention relates to the technical field of compressors, in particular to a variable-capacity piston compressor, a control method and a refrigerator.

Background

When the terminal refrigeration system selects and matches the compressors, the corresponding compressor is selected mainly according to the cold load required by the system. However, when the compressor is used for developing products with different discharge capacities, the pump body structure (the structures of the cylinder, the piston, the crankshaft connecting rod mechanism and the like, parameters of the eccentricity and the like) needs to be redesigned, and the die is opened again for casting, so that the required period and the cost are large. The conventional piston compressor cannot realize the capacity-variable function, cannot provide different refrigerating capacities under different load working conditions, is high in energy consumption under low working conditions, cannot meet the refrigerating requirement under high working conditions, and is poor in universality.

Because the conventional piston compressor in the prior art cannot realize a capacity-changing function and provide different refrigerating capacities under different load working conditions, the technical problems that the energy consumption is high under a low working condition, the refrigerating requirement cannot be met under a high working condition, the universality is poor and the like are caused, the capacity-changing piston compressor, the control method and the refrigerator are researched and designed.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defect that the piston compressor in the prior art cannot realize the capacity-variable function, cannot provide different refrigerating capacities under different load working conditions, and has poor general performance, so that the capacity-variable piston compressor, the control method and the refrigerator are provided.

In order to solve the above problems, the present invention provides a variable capacity piston compressor, comprising:

the piston is arranged in the cylinder and can reciprocate to form a compression cavity inside the cylinder, the cylinder seat is connected with the cylinder, and a valve assembly is arranged on the cylinder seat; when the exhaust pressure of the cylinder is greater than the suction pressure and the difference value between the exhaust pressure and the suction pressure is greater than a preset force, the valve assembly can control the air supplementing pipe to be communicated with the compression cavity so as to supplement air and increase enthalpy for the compression cavity; when the exhaust pressure is greater than the suction pressure and the difference value between the exhaust pressure and the suction pressure is less than or equal to a preset force, the valve assembly can control the air supplementing pipe not to be communicated with the compression cavity.

In some embodiments, the valve assembly includes a slide valve, the cylinder block is provided with a slide valve groove, the slide valve is arranged in the slide valve groove and can move in the slide valve groove, a first end of the slide valve can bear exhaust pressure, a second end of the slide valve can bear suction pressure, the slide valve is further provided with a slide valve through hole, and when the difference between the exhaust pressure and the suction pressure of the cylinder is greater than a preset force, the slide valve can be driven by differential pressure to move so as to communicate the air supplement pipe with the compression cavity through the slide valve through hole; when the difference value between the exhaust pressure and the suction pressure of the cylinder is smaller than or equal to a preset force, the slide valve can move to enable the air supplementing pipe and the compression cavity to be disconnected and communicated with the slide valve through hole.

In some embodiments, the positive displacement piston compressor further comprises a housing, the cylinder and the cylinder block are both disposed in the housing, a suction space is disposed inside the housing, the suction space has a suction gas therein, the suction space is located outside the cylinder and communicates with a suction passage of the cylinder, and the second end of the slide valve can communicate with the suction space to introduce the suction gas to provide a suction pressure.

In some embodiments, the valve assembly further comprises a first limiting part, at least part of the first limiting part is arranged in the slide valve groove, the first limiting part is arranged on one side of the slide valve facing the suction space, and a first communication channel is arranged inside the first limiting part and can introduce suction gas to act on the second end of the slide valve.

In some embodiments, the valve assembly further comprises a second limiting part and an elastic structure, wherein the second limiting part and the elastic structure are both arranged in the slide valve groove and are positioned on one side of the slide valve, which faces the suction space; the second limiting part is of a sleeve structure and is at least partially sleeved on the periphery of the first limiting part, at least part of the elastic structure is sleeved on the first limiting part and is located on the periphery of the outer portion of the second limiting part, one end of the elastic structure can be connected with the second limiting part, and the other end of the elastic structure can be connected with the sliding valve so as to apply elastic force, far away from the direction of the second limiting part, to the sliding valve, and provide the preset force.

In some embodiments, the first limiting part is also in the structure of a limiting sleeve, the first limiting part and the second limiting part are both fixedly arranged on the cylinder block, a second communication channel is arranged inside the second limiting part, at least part of the structure of the first limiting part is arranged in the second communication channel, and the second communication channel can introduce suction gas from the suction space and act on the second end of the sliding valve through the first communication channel and the sliding valve groove in sequence.

In some embodiments, the elastic structure is a spring, one end of the spring is always abutted with the second limiting part, and the other end of the spring is always abutted with the slide valve; the periphery of the slide valve is also provided with a sealing part.

In some embodiments, a first bypass hole and a second bypass hole are further formed in the cylinder block, one end of the first bypass hole is communicated with the compression cavity, the other end of the first bypass hole is communicated with the slide valve groove, one end of the second bypass hole is communicated with the air supplementing pipe, and the other end of the second bypass hole is communicated with the slide valve groove; when the difference between the exhaust pressure and the suction pressure of the cylinder is smaller than or equal to the preset force, one end of the slide valve through hole is disconnected from the first bypass hole, and the other end of the slide valve through hole is disconnected from the second bypass hole.

In some embodiments, the inflation tube comprises an inner inflation tube and an outer inflation tube; and comprises the following components: the inner air supplement pipe is located inside the shell, one end of the outer air supplement pipe is communicated with one end of the inner air supplement pipe, the other end of the outer air supplement pipe penetrates through the outer portion of the shell, and the other end of the inner air supplement pipe is communicated with the second bypass hole.

In some embodiments, the positive displacement piston compressor further comprises a cylinder head, the cylinder head being in communication with the cylinder to seal the compression chamber, the cylinder head having a discharge chamber disposed thereon, the discharge chamber being in communication with the compression chamber for introducing a discharge gas, the first end of the slide valve being communicable with the discharge chamber for introducing a discharge gas to provide a discharge pressure;

one end of the spool valve groove can be communicated with the exhaust cavity of the cylinder cover and is positioned on one side of the first end of the spool valve; the other end of the spool valve groove can communicate with the suction space and is located at one side of the second end of the spool valve.

In some embodiments, an exhaust valve plate is further arranged between the cylinder cover and the cylinder, a third communication channel is arranged on the position, opposite to the exhaust cavity, of the exhaust valve plate, one end of the third communication channel is communicated with the exhaust cavity, and the other end of the third communication channel is opposite to and communicated with the slide valve groove, so that the exhaust cavity is communicated with the slide valve groove through the third communication channel.

In some embodiments, the valve assembly further comprises a control valve disposed on the air supply pipe, and the control valve is controlled to be opened when a difference between an exhaust pressure and an intake pressure of the cylinder is greater than a preset force; and when the difference value between the exhaust pressure and the suction pressure of the cylinder is smaller than or equal to a preset force, the control valve is controlled to be closed.

The present invention further provides a control method of the variable displacement piston compressor, which includes: a detection step of detecting an exhaust pressure and an intake pressure of the cylinder;

a judging step of judging a relationship among the exhaust pressure, the suction pressure and the preset force;

a control step of controlling the control valve to open when the difference between the exhaust pressure and the suction pressure is greater than a preset force; and when the difference value between the exhaust pressure and the suction pressure is smaller than or equal to a preset force, controlling the control valve to close.

The invention also provides a refrigerator which comprises the variable-capacity piston compressor.

The variable-capacity piston compressor, the control method and the refrigerator provided by the invention have the following beneficial effects:

the invention can automatically and effectively control the communicated air supplement of the air supplement pipe through the valve component arranged on the cylinder seat, can automatically control the air supplement pipe to be communicated with the compression cavity to supplement air and increase enthalpy when the exhaust pressure of the cylinder is more than the preset force of the suction pressure, and can automatically control the air supplement pipe to be not communicated with the compression cavity when the exhaust pressure of the cylinder is less than or equal to the suction pressure plus the preset force; therefore, the invention can realize the capacity-changing function, automatically control whether to supplement air according to the size of the working condition (exhaust pressure), realize the low-working-condition and low-refrigerating-capacity operation and reduce the energy consumption; the high-capacity compressor runs with large refrigerating capacity under high working conditions, meets the refrigerating requirement and improves the general performance of the compressor.

Drawings

Fig. 1 is a schematic view of an internal structure of a prior art piston compressor;

FIG. 2 is a schematic diagram of the internal structure of the piston compressor of the present invention during variable volume light load;

FIG. 3 is a schematic diagram of the pump body structure of the piston compressor of the present invention under variable volume light load;

FIG. 4 is a schematic view of the internal structure of the piston compressor of the present invention during the enthalpy increasing by air supply;

FIG. 5 is a schematic diagram of the pump body structure of the piston compressor of the present invention during enthalpy increase by air supply;

FIG. 6 is a schematic view of the structure of the cylinder block of the piston compressor of the present invention;

fig. 7 is a structural view illustrating a valve assembly of the reciprocating compressor of the present invention.

The reference numerals are represented as:

1. a cylinder; 2. a cylinder block; 3. a piston; 4. a gas supplementing pipe; 5. a compression chamber; 6. a spool valve; 7. a spool valve groove; 8. a spool through hole; 9. a cylinder head; 10. an exhaust chamber; 11. a housing; 12. a suction space; 13. a first limiting part; 14. a first communication channel; 15. a second limiting component; 16. an elastic structure; 17. a second communication channel; 18. a sealing member; 19. an exhaust valve plate; 20. a third communication channel; 21. a first bypass hole; 22. a second bypass hole; 23. an inner air supply pipe; 24. an external air supply pipe; 25. an air suction pipe; 26. an exhaust pipe; 27. a process tube; 28. a check valve.

Detailed Description

As shown in fig. 2 to 7, the present invention provides a variable capacity piston compressor, which includes:

the piston 3 is arranged in the cylinder 1 and can reciprocate so as to form a compression cavity 5 inside the cylinder 1, the cylinder block 2 is connected with the cylinder 1, and a valve assembly is arranged on the cylinder block 2; when the exhaust pressure of the cylinder 1 is greater than the suction pressure and the difference value between the exhaust pressure and the suction pressure is greater than a preset force, the valve assembly can control the air supplementing pipe 4 to be communicated with the compression cavity 5 so as to supplement air and increase enthalpy for the compression cavity 5; when the exhaust pressure is greater than the suction pressure and the difference value between the exhaust pressure and the suction pressure is less than or equal to a preset force, the valve assembly can control the air supplementing pipe 4 not to be communicated with the compression cavity 5.

The invention can automatically and effectively control the communicated air supplement of the air supplement pipe through the valve component arranged on the cylinder seat, can automatically control the air supplement pipe to be communicated with the compression cavity to supplement air and increase enthalpy when the exhaust pressure of the cylinder is more than the preset force of the suction pressure, and can automatically control the air supplement pipe to be not communicated with the compression cavity when the exhaust pressure of the cylinder is less than or equal to the suction pressure plus the preset force; therefore, the invention can realize the capacity-changing function, automatically control whether to supplement air according to the size of the working condition (exhaust pressure), realize the low-working-condition and low-refrigerating-capacity operation and reduce the energy consumption; the high-capacity compressor runs with large refrigerating capacity under high working conditions, meets the refrigerating requirement and improves the general performance of the compressor.

The present invention can have the following effects:

1. the variable-capacity light-load and air-supply enthalpy-increasing structure is provided, so that the piston compressor is wide in cold coverage range, strong in working condition adapting capacity, strong in matching refrigerating system capacity and low in investment cost;

2. a mechanical structure (such as a refrigerator) suitable for a piston compressor is provided, and the reliability, the service life and the application range of the compressor are improved while the function is satisfied.

Fig. 1 is a diagram of a complete machine in the prior art, a cylinder base side has no bypass hole, the complete machine has no air replenishing channel, and the complete machine is a piston compressor with fixed displacement.

The invention provides a variable-capacity light load and air and enthalpy increasing structural component, which mainly has the function of adjusting the displacement along with the load change of a refrigerating system. The specific implementation mode is that the gas force of the pressure difference stroke of the suction and the exhaust of the refrigerating system and the spring force borne by the slide valve form dynamic balance to control the slide valve to reciprocate in the slide valve groove, and meanwhile, the opening of the air supplementing pipe is determined by the refrigerating capacity required by the system, so that the refrigerating capacity requirements of the system under different loads are met, and the variable capacity adjusting function of the compressor is realized.

In some embodiments, the valve assembly includes a slide valve 6, a slide valve groove 7 is disposed on the cylinder block 2, the slide valve 6 is disposed in the slide valve groove 7 and can move in the slide valve groove 7, a first end of the slide valve 6 can bear exhaust pressure, a second end of the slide valve 6 can bear suction pressure, a slide valve through hole 8 is further formed on the slide valve 6, and when a difference between the exhaust pressure and the suction pressure of the cylinder 1 is greater than a preset force, the slide valve 6 can be driven to move by a pressure difference to communicate the air supplement pipe 4 with the compression cavity 5 through the slide valve through hole 8; when the difference value between the exhaust pressure and the suction pressure of the cylinder 1 is smaller than or equal to a preset force, the slide valve 6 can move to disconnect the air supplementing pipe 4 and the compression cavity 5 from the slide valve through hole 8.

The valve component of the invention is a preferable structure form, namely, the valve component comprises a slide valve, a cylinder seat is provided with a slide valve groove, the slide valve can move in the slide valve groove, a first end of the slide valve bears exhaust pressure, and a second end bears suction pressure, thus effectively converting the working condition into the motion mode of the slide valve, namely, the slide valve is automatically controlled to move towards the low pressure direction under the high working condition so that a slide valve through hole of the slide valve is communicated between a compression cavity and an air supply pipe, thereby effectively realizing the function of automatic air supply and enthalpy increase under the high working condition, and the slide valve is driven to automatically move by the resultant force of pressure and the like to break the communication between the compression cavity and the air supply pipe under the low working condition, thereby automatically realizing the effect of non-air supply under the low working condition, thereby effectively and automatically realizing the effects of high working condition air supply and enthalpy increase and non-air supply under the low working condition through the structure forms of the slide valve and the slide valve groove, enhancing the performance of the applicable working condition size of the compressor, and improving the universality thereof.

In some embodiments, the variable displacement piston compressor further comprises a housing 11, the cylinder 1 and the cylinder block 2 are both disposed in the housing 11, a suction space 12 is disposed inside the housing 11, the suction space 12 has suction gas therein, the suction space 12 is located outside the cylinder 1 and communicates with a suction passage of the cylinder 1, and the second end of the slide valve 6 can communicate with the suction space 12 to introduce the suction gas to provide suction pressure. The invention also can effectively form a suction space for sucking air in the shell through the structure of the shell, the suction space provides suction air with low pressure, and the suction space effectively acts on the second end of the slide valve, thereby providing conditions for the slide valve to provide pressure difference comparison according to the working condition.

In some embodiments, the valve assembly further comprises a first limiting part 13 (preferably, a limiting sleeve, the same applies below), at least part of the first limiting part 13 is arranged in the slide valve groove 7, the first limiting part 13 is arranged on the side of the slide valve 6 facing the suction space 12, the first limiting part can limit the second end of the slide valve, a first communication channel 14 is arranged inside the first limiting part 13, and the first communication channel 14 can introduce suction gas to act on the second end of the slide valve 6.

The valve assembly of the present invention further preferably further comprises a first limiting member disposed in the spool groove to effectively limit the moving position of the second end of the spool to prevent the spool from coming out of the spool groove, and a first communicating channel is disposed inside the first limiting member to effectively guide the low-pressure suction gas in the suction space to the second end of the spool to provide conditions for controlling the spool according to the size of the working condition.

In some embodiments, the valve assembly further comprises a second limiting part 15 (preferably a limiting sleeve, the same applies below) and an elastic structure 16, and the second limiting part 15 and the elastic structure 16 are both arranged in the spool valve groove 7 and are positioned on one side of the spool valve 6 facing the suction space 12; the second limiting part 15 is of a sleeve structure and is at least partially sleeved on the periphery of the first limiting part 13, at least part of the elastic structure 16 is sleeved on the first limiting part 13 and is located on the periphery of the outer portion of the second limiting part 15, one end of the elastic structure 16 can be connected with the second limiting part 15, and the other end of the elastic structure 16 can be connected with the sliding valve 6 to apply elastic force to the sliding valve 6, wherein the elastic force is far away from the direction of the second limiting part 15, so that the preset force is provided.

The valve assembly of the invention is further preferable in structural form, the second limiting part can provide abutting supporting force for the elastic structure and limit the elastic structure, the other end of the elastic structure is connected with the slide valve, so as to effectively provide elastic thrust for the slide valve, the elastic thrust can be provided as preset force to act on the slide valve, and when the difference between the exhaust pressure and the suction pressure of the slide valve is greater than the preset force, the slide valve can be driven to move so as to communicate the air supplementing pipe with the compression cavity through the slide valve through hole; when the difference value between the exhaust pressure and the suction pressure of the cylinder is smaller than or equal to a preset force, the elastic force can provide elastic thrust to drive the slide valve to move, so that the air supplementing pipe and the compression cavity are disconnected from the slide valve through hole; the effects of air supply and enthalpy increase under high working conditions and air non-supply under low working conditions are realized.

In some embodiments, the first limiting member 13 is also in the form of a limiting sleeve, the first limiting member 13 and the second limiting member 15 are both fixedly disposed on the cylinder block 2, the second limiting member 15 has a second communication channel 17 inside, at least a part of the first limiting member 13 is disposed in the second communication channel 17, and the second communication channel 17 can introduce suction gas from the suction space 12 and act on the second end of the sliding valve 6 through the first communication channel 14 and the sliding valve groove 7 in sequence.

The first limiting part and the second limiting part are both in a limiting sleeve structure, the second limiting part is partially sleeved on the periphery of the first limiting part, an elastic structure is arranged between the second limiting part and the sliding valve, and the first limiting part and the second limiting part are both in a structure fixed on a cylinder seat, so that the first limiting part can effectively limit the sliding valve, the second limiting part can provide elastic supporting force for the spring and can effectively limit the spring, and a communication channel in the second limiting part can accommodate the first limiting part and can introduce gas into the sliding valve groove and enter the sliding valve groove through the first communication channel to act on the second end of the sliding valve, so that the condition for controlling the movement of the sliding valve according to the working condition is provided.

In some embodiments, the elastic structure 16 is a spring, one end of which always abuts against the second limiting component 15, and the other end of which always abuts against the slide valve 6; the outer periphery of the slide valve 6 is also provided with a sealing member 18. The two ends of the spring are respectively connected with the second limiting part and the sliding valve so as to provide elastic force for the sliding valve all the time and improve the accuracy of automatic control of the sliding valve; the sealing component is arranged on the periphery of the sliding valve, so that the sealing performance of the sliding valve in the movement process can be improved, and the leakage and the blow-by between the gas at the first end and the gas at the second end of the sliding valve are prevented.

Referring to fig. 6 and 7, which are structural diagrams of a cylinder block and a variable-capacity light-load and air-supply enthalpy-increasing assembly (valve assembly) in the technology of the invention, a side hole I21 and a slide valve groove 7 are arranged on the cylinder side of the cylinder block, a slide valve through hole 8 is arranged on the slide valve 6, a first limit part 13 and a second limit part 15 realize double limit functions in the slide valve groove 7, the second limit part 15 plays a role of a limit spring and a constraint limit part I13, and the first limit part 13 plays a role of a limit slide valve 6. One side (left side) of the slide valve groove 7 is communicated with a cylinder cover exhaust high-pressure cavity, and the other side (right side) is communicated with an air suction low-pressure side. The sealing ring (the sealing part 18) plays a role in preventing the exhaust high-pressure cavity from channeling air to the low-pressure cavity to cause the functional failure of the structure, the arrangement of the rigidity and the initial state of the spring can design reasonable spring force according to the change rule of the pressure difference of suction and exhaust under different working conditions of the system, and the feasibility and the reliability of the structure are enhanced. The maximum deformation of the spring can be adjusted by adjusting the position of the first limiting part 13 relative to the second limiting part 15. The pretightening force of the spring can be adjusted by adjusting the position of the second limiting component 15 relative to the slide valve slot 7, so that the application requirements of different environmental temperatures in different regions can be met.

In some embodiments, the cylinder block 2 is further provided with a first bypass hole 21 and a second bypass hole 22, one end of the first bypass hole 21 is communicated with the compression cavity 5, the other end of the first bypass hole is communicated with the slide valve groove 7, one end of the second bypass hole 22 is communicated with the air supplement pipe 4, and the other end of the second bypass hole is communicated with the slide valve groove 7; when the difference between the exhaust pressure and the suction pressure of the cylinder 1 is greater than a preset force, the sliding valve 6 can move to the position where one end of the sliding valve through hole 8 is in butt joint communication with the first bypass hole 21, the other end of the sliding valve through hole 8 is in butt joint communication with the second bypass hole 22, when the difference between the exhaust pressure and the suction pressure of the cylinder 1 is less than or equal to the preset force, one end of the sliding valve through hole 8 is disconnected from the first bypass hole 21, and the other end of the sliding valve through hole 8 is disconnected from the second bypass hole 22.

The compression cavity can be communicated with the sliding valve groove through the first bypass hole, the sliding valve groove can be communicated with the air supplementing pipe through the second bypass valve, and the first bypass hole and the second bypass hole are preferably opposite to each other, so that the sliding valve through hole is positioned between the first bypass hole and the second bypass hole and is communicated with the first bypass hole and the second bypass hole in sequence when the two bypass holes are opposite to each other, and the effect of communicating and supplementing air is achieved; when the slide valve moves according to the working condition until the slide valve through hole is not opposite to the first bypass hole and the second bypass hole respectively, the communication between the slide valve through hole and the compression cavity and the air supply pipe is cut off, and the air supply pipe is further controlled to be closed through a control valve on the air supply pipe, so that air supply is prevented from entering the compression cavity, the effects of air supply enthalpy increase in high working conditions and normal operation in low working conditions are achieved, and the universality is improved.

The invention provides a structure for increasing enthalpy by variable volume light load and air supplement, which adopts a slide valve, a spring, a limiting sleeve, an air supplement pipe and the like to realize the functions of variable volume light load and air supplement enthalpy; the pressure difference of the air suction and the air exhaust of the refrigerating system is increased (decreased and decreased) along with the increase of the load of the refrigerating system, when the system is under the condition of low load, the pressure difference of the air suction and the air exhaust of the system is small, the gas force is smaller than the spring force, and the slide valve is tightly attached to the position limiting part of the left cylinder cover under the action of the spring force; when the system is in a high-load condition, the pressure difference of air suction and exhaust of the system is large, the gas force is larger than the spring force, the compression spring pushes the sliding valve to move rightwards and cling to the first limiting sleeve, the first bypass hole 21 on the cylinder seat is overlapped with the axis of the through hole 8 of the sliding valve, the compression cavity of the cylinder is communicated with the first bypass hole 21 and the air supplementing pipe, and whether the air supplementing pipe is opened or not depends on the refrigerating capacity required by the refrigerating system.

Secondly, through the translation and the limiting of the sliding valve in the sliding valve groove, the pretightening force of the spring on the sliding valve can be adjusted, the reasonable pretightening force is designed according to the change rule of the suction and exhaust pressure difference of the system under different working conditions, and the feasibility and the reliability of the structure are enhanced.

In some embodiments, the endotracheal tube 4 comprises an inner endotracheal tube 23 and an outer endotracheal tube 24; and comprises the following components: the inner air supplement pipe 23 is located inside the shell 11, one end of the outer air supplement pipe 24 is communicated with one end of the inner air supplement pipe 23, the other end of the outer air supplement pipe 24 penetrates through the outer portion of the shell 11, and the other end of the inner air supplement pipe 23 is communicated with the second bypass hole 22. The air supplementing pipe preferably comprises an inner air supplementing pipe positioned in the shell and an outer air supplementing pipe communicated with the inner air supplementing pipe, air supplementing gas can be introduced through the outer air supplementing pipe, and air supplementing gas enters the compression cavity through the inner air supplementing pipe, the second bypass hole, the through hole of the sliding valve and the first bypass hole, so that air supplementing can be effectively completed.

In some embodiments, the variable displacement piston compressor further comprises a cylinder head 9, the cylinder head 9 is connected with the cylinder 1 to seal the compression cavity 5, a discharge cavity 10 is arranged on the cylinder head 9, the discharge cavity 10 is communicated with the compression cavity 5 to introduce discharge gas, and the first end of the slide valve 6 can be communicated with the discharge cavity 10 to introduce discharge gas to provide a discharge pressure;

one end of the spool valve spool 7 is communicable with the exhaust chamber 10 of the cylinder head 9 and is located on one side of the first end of the spool valve 6; the other end of the spool valve slot 7 can communicate with the suction space 12 and is located at one side of the second end of the spool valve 6.

The variable displacement piston compressor is further preferred in structural form, the cylinder cover is provided with an exhaust cavity, the exhaust cavity is communicated with the compression cavity to introduce high-pressure gas, the high-pressure gas of the exhaust cavity can be communicated to the first end of the sliding valve to provide high-pressure for the sliding valve, one end of the sliding valve groove is preferably communicated with the exhaust cavity through an exhaust valve plate, the other end of the sliding valve groove is preferably communicated with the suction space to provide suction low-pressure for the second end of the sliding valve, and the function and the effect of providing high-pressure for the first end of the sliding valve are effectively achieved.

In some embodiments, an exhaust valve plate 19 is further disposed between the cylinder head 9 and the cylinder 1, a third communication channel 20 is disposed on the exhaust valve plate 19 at a position opposite to the exhaust cavity 10, one end of the third communication channel 20 is communicated with the exhaust cavity 10, and the other end of the third communication channel is opposite to and communicated with the slide valve groove 7, so that the exhaust cavity 10 is communicated with the slide valve groove 7 through the third communication channel 20. The invention can ensure that the internal pressure of the compression cavity can be opened only when reaching the preset exhaust pressure through the arrangement of the exhaust valve plate, and the third communication channel arranged on the exhaust valve plate can communicate the exhaust cavity on the cylinder cover with the slide valve groove, thereby completing the function of providing high pressure to the first end of the slide valve.

In some embodiments, the valve assembly further comprises a control valve disposed on the air supply pipe 4, and the control valve is controlled to be opened when a difference between an exhaust pressure and a suction pressure of the cylinder 1 is greater than a preset force; and when the difference value between the exhaust pressure and the suction pressure of the cylinder 1 is smaller than or equal to a preset force, the control valve is controlled to be closed. The air supply pipe is provided with a control valve, the air supply pipe can be adaptively controlled according to the working condition, when the difference value between the exhaust pressure and the suction pressure is greater than the preset force, the slide valve is driven by the pressure to complete the communication between the compression cavity and the air supply pipe through the slide valve through hole, and at the moment, the control valve on the air supply pipe needs to be correspondingly opened to effectively complete the air supply effect on the compression cavity; when the difference value between the exhaust pressure and the suction pressure is smaller than or equal to the preset force, the slide valve is driven by the elastic force to enable the slide valve through hole to be not communicated with the compression cavity and the air supplementing pipe, and at the moment, the slide valve enters the compression cavity from a position outside the slide valve through hole in order to prevent the air supplementing pipe from ventilating, so that the control valve is closed, and the effect of not supplementing air under the low working condition is effectively and accurately achieved.

For fig. 2 and 3, the compressor in this state realizes the variable capacity light load function. The pressure difference is not established in the suction and exhaust before the compressor is started, the slide valve is tightly attached to the position limiting part of the cylinder cover on the left side of the slide valve under the action of the spring force, the load is small when the compressor is started, the compressor is easy to start, and the energy consumption is lower. After the compressor is started, the system establishes a certain air suction and exhaust pressure difference, and when the system is in a low-load operation condition (namely, the required cold quantity is small, and the required displacement of the compressor is small), the air suction and exhaust pressure difference is small, and the gas force is still smaller than the spring force and is tightly attached to the position limited by the cylinder cover. As shown in figure 3, a check valve 28 such as a reed valve or a one-way valve is arranged at the internal air supply pipe, partial air in the cylinder flows out of the first bypass hole 21 formed in the cylinder seat before the piston runs to completely cover the first bypass hole 21, and due to the arrangement of the one-way valve, the air can only pass through the first limiting part 13 and the second limiting part 15 and is discharged to a low-pressure air suction cavity (namely an air suction space 12) of the compressor shell, so that the actual compression amount of the air refrigerant is reduced, the discharge capacity of the compressor is reduced, and the power consumption is reduced.

For fig. 4 and 5, the compressor realizes the functions of air supply and enthalpy increase in this state. When the system is in a high-load operation condition (namely, the required cold quantity is large, and the required displacement of the compressor is large), the air suction and exhaust pressure difference formed by the exhaust high-pressure cavity and the air suction low-pressure cavity is large, at the moment, the air force is larger than the spring force, the slide valve starts to move rightwards, the spring is compressed, and finally the limiting component I13 is tightly attached, and at the moment, the bypass hole I21 and the slide valve through hole 8 of the slide valve are positioned on the same axis. When the original compressor is in full-load operation, the system requirement can be met, the air supplementing channel is not selected to be opened, and due to the arrangement of the one-way valve, the gas refrigerant in the cylinder does not leak; when the refrigerating capacity required by the system is larger, the air supplementing channel is selectively opened (namely the control valve is opened), the air supplementing gas pressure is larger than the gas pressure in the cylinder, the air supplementing gas enters the cylinder to be mixed with the original gas for compression after sequentially passing through the inner air supplementing pipe, the sliding valve through hole 8 and the bypass hole one 21, the gas compression capacity of the compressor is increased, and the discharge capacity is increased.

When the refrigerating system is switched from high load to low load, the pressure difference of air suction and exhaust is reduced, the spring force is greater than the gas force, the spring pushes the slide valve to move leftwards and is finally attached to the position limit of the cylinder cover, and at the moment, the compressor realizes the function of capacity change and light load.

Therefore, the invention develops a piston compressor with moderate displacement, and the compressor can realize 3 operation modes by assembling the structure of the invention; when the system runs at low load, the compressor can realize the function of variable capacity and light load; when the original displacement full-load operation of the compressor can meet the system requirement, the air supplementing channel can be selected not to be opened; when the system runs at a higher load, the air supplementing channel is opened to increase the air displacement.

The present invention also provides a control method of the variable displacement piston compressor, which includes: a detection step of detecting an exhaust pressure and an intake pressure of the cylinder 1;

a judging step of judging a relationship among the exhaust pressure, the suction pressure and the preset force;

a control step of controlling the control valve to open when the difference between the exhaust pressure and the suction pressure is greater than a preset force; and when the difference value between the exhaust pressure and the suction pressure is smaller than or equal to a preset force, controlling the control valve to close.

The control method of the control valve can perform adaptive control according to the working condition, and when the difference value between the exhaust pressure and the suction pressure is greater than the preset force, the control valve on the air supply pipe is opened to effectively complete the air supply effect to the compression cavity; and when the difference value between the exhaust pressure and the suction pressure is smaller than or equal to the preset force, the control valve is closed, and the effect of not supplementing air under the low working condition is effectively and accurately realized.

The invention also provides a refrigerator which comprises the variable-capacity piston compressor.

The invention provides a variable-capacity light load and air-supply enthalpy-increasing structure suitable for a reciprocating piston compressor and a refrigerator, compared with the prior piston compressor technology, the piston compressor is provided with the variable-capacity light load and air-supply enthalpy-increasing mechanical structure, and under the low-load (small displacement required) working condition of a refrigeration system, the compressor realizes the function of variable-capacity light load and reduces energy consumption; under the high load (large displacement is needed) working condition of the refrigerating system, the compressor realizes the functions of air supply and enthalpy increase, and can quickly refrigerate to meet the working requirements of the refrigerating system. Meanwhile, the starting load of the compressor is small when the capacity is changed and the load is light, and the starting capacity is improved; when the air is supplemented and the enthalpy is increased, the capability of the compressor for adapting to the working condition with low evaporation temperature is improved. Therefore, the effect of supplementing air to meet the refrigeration requirement under the low working condition without supplementing air to reduce energy consumption and the high working condition is realized, the compressor is suitable for the working condition in a wider range, and the universal performance of the compressor suitable for various refrigerators is improved.

The above description is intended to be illustrative of the preferred embodiment of the present invention and should not be taken as limiting the invention, but rather, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims (14)

1. A variable capacity piston compressor characterized by: the method comprises the following steps:

the air compressor comprises an air cylinder (1), an air cylinder seat (2), a piston (3) and an air supplementing pipe (4), wherein the piston (3) is arranged in the air cylinder (1) and can reciprocate so as to form a compression cavity (5) inside the air cylinder (1), the air cylinder seat (2) is connected with the air cylinder (1), and a valve assembly is arranged on the air cylinder seat (2); when the exhaust pressure of the cylinder (1) is greater than the suction pressure and the difference value between the exhaust pressure and the suction pressure is greater than a preset force, the valve assembly can control the air supplementing pipe (4) to be communicated with the compression cavity (5) so as to supplement air and increase enthalpy for the compression cavity (5); when the exhaust pressure is greater than the suction pressure and the difference value between the exhaust pressure and the suction pressure is less than or equal to a preset force, the valve assembly can control the air supplementing pipe (4) not to be communicated with the compression cavity (5).

2. The variable capacity piston compressor of claim 1, wherein:

the valve assembly comprises a slide valve (6), a slide valve groove (7) is formed in the cylinder seat (2), the slide valve (6) is arranged in the slide valve groove (7) and can move in the slide valve groove (7), the first end of the slide valve (6) can bear exhaust pressure, the second end of the slide valve (6) can bear suction pressure, a slide valve through hole (8) is further formed in the slide valve (6), and when the difference value between the exhaust pressure and the suction pressure of the cylinder (1) is larger than a preset force, the slide valve (6) can be driven to move by pressure difference so as to communicate the air supplementing pipe (4) with the compression cavity (5) through the slide valve through hole (8); when the difference value between the exhaust pressure and the suction pressure of the cylinder (1) is smaller than or equal to a preset force, the slide valve (6) can move to enable the air supplementing pipe (4) and the compression cavity (5) to be disconnected and communicated with the slide valve through hole (8).

3. The variable capacity piston compressor of claim 2, wherein:

the variable displacement piston compressor further comprises a shell (11), the cylinder (1) and the cylinder seat (2) are arranged in the shell (11), a suction space (12) is arranged inside the shell (11), suction gas is arranged in the suction space (12), the suction space (12) is located outside the cylinder (1) and communicated with a suction channel of the cylinder (1), and the second end of the sliding valve (6) can be communicated with the suction space (12) to introduce the suction gas so as to provide suction pressure.

4. A variable capacity piston compressor according to claim 3, wherein:

the valve assembly further comprises a first limiting part (13), at least part of the first limiting part (13) is arranged in the sliding valve groove (7), the first limiting part (13) is arranged on one side, facing the suction space (12), of the sliding valve (6), and a first communication channel (14) is arranged inside the first limiting part (13), and suction gas can be introduced into the first communication channel (14) to act on the second end of the sliding valve (6).

5. The variable capacity piston compressor of claim 4, wherein:

the valve assembly further comprises a second limiting part (15) and an elastic structure (16), wherein the second limiting part (15) and the elastic structure (16) are arranged in the sliding valve groove (7) and are positioned on one side, facing the suction space (12), of the sliding valve (6); the second limiting part (15) is of a sleeve structure and is at least partially sleeved on the periphery of the first limiting part (13), at least part of the elastic structure (16) is sleeved on the first limiting part (13) and is located on the periphery of the outer portion of the second limiting part (15), one end of the elastic structure (16) can be connected with the second limiting part (15), and the other end of the elastic structure (16) can be connected with the sliding valve (6) to apply elastic force to the sliding valve (6) in a direction away from the second limiting part (15) so as to provide the preset force.

6. The variable capacity piston compressor of claim 5, wherein:

the first limiting part (13) is also of a limiting sleeve structure, the first limiting part (13) and the second limiting part (15) are fixedly arranged on the cylinder seat (2), a communication channel II (17) is arranged inside the second limiting part (15), at least part of the structure of the first limiting part (13) is arranged in the communication channel II (17), and the communication channel II (17) can introduce suction gas from the suction space (12) and act on the second end of the sliding valve (6) through the communication channel I (14) and the sliding valve groove (7) in sequence.

7. The variable capacity piston compressor of claim 6, wherein:

the elastic structure (16) is a spring, one end of the elastic structure is always abutted with the second limiting part (15), and the other end of the elastic structure is always abutted with the sliding valve (6); the outer periphery of the slide valve (6) is also provided with a sealing part (18).

8. A variable capacity piston compressor according to claim 3, wherein:

the cylinder seat (2) is also provided with a first bypass hole (21) and a second bypass hole (22), one end of the first bypass hole (21) is communicated with the compression cavity (5), the other end of the first bypass hole is communicated with the sliding valve groove (7), one end of the second bypass hole (22) is communicated with the air supplementing pipe (4), and the other end of the second bypass hole is communicated with the sliding valve groove (7); when the difference between the exhaust pressure and the suction pressure of the cylinder (1) is larger than a preset force, the sliding valve (6) can move to one end of the sliding valve through hole (8) to be in butt joint communication with the first bypass hole (21), the other end of the sliding valve through hole (8) to be in butt joint communication with the second bypass hole (22), when the difference between the exhaust pressure and the suction pressure of the cylinder (1) is smaller than or equal to the preset force, one end of the sliding valve through hole (8) is disconnected from the first bypass hole (21), and the other end of the sliding valve through hole (8) is disconnected from the second bypass hole (22).

9. The positive displacement piston compressor of claim 8, wherein:

the air supply pipe (4) comprises an inner air supply pipe (23) and an outer air supply pipe (24); and has the following components: interior air supplement pipe (23) are located the inside of casing (11), the one end of outer air supplement pipe (24) with the one end intercommunication of interior air supplement pipe (23), the other end of outer air supplement pipe (24) wears to establish to the outside of casing (11), the other end of interior air supplement pipe (23) with by-pass hole two (22) intercommunication.

10. A variable capacity piston compressor according to any one of claims 3-9, characterized in that:

the variable displacement piston compressor also comprises a cylinder cover (9), the cylinder cover (9) is connected with the cylinder (1) to seal the compression cavity (5), a discharge cavity (10) is arranged on the cylinder cover (9), the discharge cavity (10) is communicated with the compression cavity (5) to introduce discharge gas, and the first end of the slide valve (6) can be communicated with the discharge cavity (10) to introduce discharge gas to provide discharge pressure;

one end of the spool valve groove (7) is capable of communicating with the exhaust chamber (10) of the cylinder head (9) and is located on one side of the first end of the spool valve (6); the other end of the slide valve groove (7) can be communicated with the suction space (12) and is positioned on one side of the second end of the slide valve (6).

11. The variable capacity piston compressor of claim 10, wherein:

the exhaust valve is characterized in that an exhaust valve plate (19) is further arranged between the cylinder cover (9) and the cylinder (1), a communication channel III (20) is arranged on the exhaust valve plate (19) and opposite to the exhaust cavity (10), one end of the communication channel III (20) is communicated with the exhaust cavity (10), the other end of the communication channel III (20) is opposite to and communicated with the sliding valve groove (7), and the exhaust cavity (10) is communicated with the sliding valve groove (7) through the communication channel III (20).

12. A variable capacity piston compressor according to any one of claims 1-11, characterized in that:

the valve assembly further comprises a control valve, the control valve is arranged on the air supplementing pipe (4), and when the difference value between the exhaust pressure and the suction pressure of the cylinder (1) is larger than a preset force, the control valve is controlled to be opened; and when the difference value between the exhaust pressure and the suction pressure of the cylinder (1) is smaller than or equal to a preset force, the control valve is controlled to be closed.

13. A control method of the variable capacity piston compressor according to claim 12, characterized in that: the method comprises the following steps: a detection step of detecting an exhaust pressure and an intake pressure of the cylinder (1);

a judging step of judging a relationship among the exhaust pressure, the suction pressure and the preset force;

a control step of controlling the control valve to open when the difference between the exhaust pressure and the suction pressure is greater than a preset force; and when the difference value between the exhaust pressure and the suction pressure is smaller than or equal to a preset force, controlling the control valve to close.

14. A refrigerator, characterized in that: comprising a variable capacity piston compressor according to any of claims 1-12.

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