Refrigerant pump and refrigeration system

Abstract

The application provides a refrigerant pump and a refrigeration system. The refrigerant pump comprises a first gear pump head, a power part and a second gear pump head arranged in sequence, the power part comprises a rotating shaft and a rotor, the middle part of the rotating shaft is fixed to the rotor, and the two ends of the rotating shaft are respectively inserted into gear parts of the first gear pump head and the second gear pump head. By arranging the first gear pump head and the second gear pump head at the two ends of the power part, the force received by the two ends of the rotating shaft can be balanced, and the wear problem caused by the unbalanced force of the rotating shaft due to the eccentricity of the shaft can be avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pumps, in particular to a refrigerant pump and a refrigeration system. BACKGROUND

[0002] The number and scale of data centers are rapidly increasing, and the total energy consumption is also increasing, in which the air conditioning system accounts for more than 40% of the total energy consumption. The air conditioning system is provided with a compressor path and a refrigerant pump path, and the power of the refrigerant pump is much smaller than that of the compressor. Therefore, for a compression refrigeration system, the refrigerant pump can be used to replace the compressor to transport low-temperature refrigerant when the winter or outdoor temperature is low, which can effectively reduce the energy consumption of the system and has outstanding energy-saving effect.

[0003] The current industry refrigerant pump includes a centrifugal pump and a gear pump. The centrifugal pump has a long service life but has a serious cavitation problem. The gear pump almost has no cavitation problem but has a serious wear problem, resulting in a short service life.

[0004] Therefore, it is necessary to provide a refrigerant pump which can avoid the cavitation problem and the wear problem to improve the service life of the refrigerant pump. SUMMARY

[0005] The embodiments of the present application provide a refrigerant pump and a refrigeration system, which solve the wear problem caused by the unbalanced stress of the rotating shaft in the refrigerant pump and significantly improve the service life of the refrigerant pump.

[0006] In a first aspect, the embodiments of the present application provide a refrigerant pump, which is a pump capable of transporting refrigerant. The refrigerant, also known as coolant or snow species, can be used in air conditioners as a medium substance for heat transfer to transfer heat from a low-temperature place to a high-temperature place.

[0007] The refrigerant pump includes a first gear pump head, a power part and a second gear pump head arranged in sequence. The power part includes a rotating shaft and a rotor. The middle part of the rotating shaft is fixed to the rotor, and the two ends of the rotating shaft are respectively inserted into the gear part of the first gear pump head and the gear part of the second gear pump head. Specifically, the first gear pump head includes a first housing and a first gear part (i.e. the gear part of the first gear pump head) located in the first housing. The second gear part includes a second housing and a second gear part (i.e. the gear part of the second gear pump head) located in the second housing. The two ends of the rotating shaft are respectively inserted into the gear part of the first gear pump head and the gear part of the second gear pump head can be understood as that the first gear part and the second gear part are both provided with through holes, the rotating shaft passes through the through holes of the first gear part and the through holes of the second gear part, that is, the first gear part and the second gear part are both sleeved on the rotating shaft. It should be noted that the middle part of the rotating shaft is not strictly limited to the position of the center of the rotating shaft, but any part between the two ends can be called the middle part.

[0008] The power unit is configured to provide power to the first gear pump head and the second gear pump head. The power unit is usually an electric motor, which includes a rotating shaft, a rotor and a stator. The rotor is fixed to the rotating shaft, and the stator is sleeved on the periphery of the rotor. The stator is provided with a coil, and the stator generates a rotating magnetic field when energized. The magnetic field interacts with the magnetic field generated by the rotor, thereby driving the rotor to rotate. The rotor is fixedly connected to the rotating shaft, so the rotor drives the rotating shaft to rotate. The rotating shaft can drive the structures in the first gear pump head and the second gear pump head to rotate. The refrigerant passes through the first gear pump head and the second gear pump head to achieve the transmission and pressurization of the refrigerant.

[0009] The first gear pump head and the second gear pump head are configured to transport liquid or pressurize liquid by changing and moving the working volume formed between the pump cylinder and the meshing gears. Due to the continuous meshing of the teeth, the refrigerant is mechanically squeezed out. The pressure change of the gear pump head is relatively small, and cavitation is not easy to occur. Cavitation is a failure mode of the pump. The liquid medium vaporizes to form bubbles at the pump inlet due to excessive pressure reduction. The bubbles condense into liquid at the pump outlet due to pressure increase. The formation and disappearance of bubbles can produce a huge point burst pressure, which can cause pitting on the metal surface of the pump head, damage the pump head, and cause cavitation. In addition, the bubbles gathered in the pump head can also cause a significant decrease in the flow rate of the pump head. The gear pump head used in the present application does not rely on pressure changes to achieve the transmission and pressurization of the refrigerant. The overall pressure change is small, and cavitation almost does not occur.

[0010] The gear pump head is an eccentric structure. When in operation, the rotating shaft is subjected to unbalanced stress, which can easily cause wear and tear, thereby reducing the service life of the refrigerant pump. The gear pump head includes an external meshing pump head and an internal meshing pump head. Taking the internal meshing pump head as an example, the internal meshing pump head includes an internal gear and an external gear. The external gear is sleeved on the outside of the internal gear and meshes with the internal gear. The internal gear is connected to the rotating shaft, which can drive the internal gear to rotate. The internal gear drives the external gear to rotate. The axis of the internal gear coincides with the axis of the rotating shaft, and the axis of the external gear does not coincide with the axis of the rotating shaft and changes constantly with the rotation of the rotating shaft, resulting in an eccentric structure of the gear pump head. When the gear pump head is arranged at only one end of the rotor in the prior art, the rotating shaft is subjected to unbalanced stress during operation, which can cause tilting. This can cause serious wear and tear of the structure connected to the rotating shaft, such as the bearing. Bearings are arranged between the first gear pump head and the rotor and between the second gear pump head and the rotor. The bearings are sleeved on the rotating shaft.

[0011] The first gear pump head and the second gear pump head are symmetrically arranged relative to the rotor in the present application. The symmetric arrangement is not strictly limited to the distance between the first gear pump head and the rotor being equal to the distance between the second gear pump head and the rotor. The distance between the first gear pump head and the rotor and the distance between the second gear pump head and the rotor can also be different during specific arrangement. As long as the first gear pump head and the second gear pump head are arranged at opposite ends of the rotor, they can be understood as being arranged symmetrically.

[0012] The application sets the gear pump head, specifically the first gear pump head and the second gear pump head, at both ends of the power part, i.e. symmetrically, to balance the force received by the shaft at both ends, avoid the shaft imbalance caused by the shaft eccentricity, the shaft inclination and the aggravation of the bearing wear, improve the reliability and service life of the refrigerant pump, and thus improve the quality and application value of the refrigerant pump. The refrigerant pump has simple structure and low cost.

[0013] The refrigerant pump has a shell, and the first gear pump head, the power part and the second gear pump head are arranged in the shell, i.e. the motor is arranged in the shell. Compared with the motor arranged outside, the refrigerant pump has good sealing performance, high reliability, simple structure and small size.

[0014] In a possible implementation, in the axial direction of the shaft, the gear part of the first gear pump head is in sliding connection with the shaft, and the shaft can drive the gear part to rotate. The stator of the power part is fixed to the inner surface of the shell of the refrigerant pump, and the rotor is arranged correspondingly. In the actual assembly process, the position of the rotor may deviate in the axial direction. In the operation process of the power part, the rotor will automatically adjust to the preset position. When the gear part is fixedly connected with the shaft, in the automatic adjustment process of the rotor, the rotor will drive the shaft to move in the axial direction of the shaft, the shaft will drive the gear part to move, and the gear part will hit the shell of the first gear pump head, aggravate the friction, and cause serious wear of the gear part and the shell. In this implementation, the gear part of the first gear pump head is in sliding connection with the shaft, so that in the process of the rotor driving the shaft to move, the shaft and the gear part of the first gear pump head slide, the shaft cannot drive the gear part of the first gear pump head to move in the axial direction, and thus there is no wear problem, and the reliability of the first gear pump head is improved. The structure of the second gear pump head is the same as that of the first gear pump head, which will not be described here.

[0015] In a possible implementation, the gear part of the first gear pump head is provided with a rectangular through hole, and the end of the rotating shaft is provided with a rectangular block which passes through the rectangular through hole. Specifically, the gear part includes a first gear and a second gear which are engaged with each other; the first gear includes a connecting part and a tooth part surrounding the connecting part, and the second gear is engaged with the tooth part; the connecting part is provided with a rectangular through hole; the rotating shaft includes a main shaft and an end part located on one side of the main shaft, and the rotor is sleeved on the main shaft, and the end part is provided with a rectangular block. The first gear pump head can be an internal gear pump head, or an external gear pump head, and the present embodiment takes the internal gear pump head as an example. The first gear is an internal gear, the second gear is an external gear, the second gear is sleeved on the first gear and engaged with the first gear, the first gear is in sliding connection with the rotating shaft, and the rotating shaft can drive the first gear to rotate. The rectangular block and the rectangular through hole are matched in a manner that can realize the sliding of the rotating shaft and the gear part of the first gear pump head in the axial direction, avoid wear and tear, and also realize the rotation of the rotating shaft and the gear part of the first gear pump head in the circumferential direction of the rotating shaft.

[0016] In other implementations, the gear part of the first gear pump head can be provided with a triangular through hole, and the end of the rotating shaft is in a triangular structure. The triangular through hole and the triangular structure are matched in a manner that can realize the sliding of the rotating shaft and the gear part of the first gear pump head in the axial direction, avoid wear and tear, and also realize the rotation of the rotating shaft and the gear part of the first gear pump head in the circumferential direction, or the gear part of the first gear pump head can be a rhombic through hole, and the end of the rotating shaft is in a rhombic structure. The rhombic through hole and the rhombic structure are matched in a manner that can realize the sliding of the rotating shaft and the gear part of the first gear pump head in the axial direction, avoid wear and tear, and also realize the rotation of the rotating shaft and the gear part of the first gear pump head in the circumferential direction.

[0017] In a possible implementation, the first gear pump head includes a housing, the gear part of the first gear pump head is located in the housing, and the housing is fixed to the shell of the refrigerant pump. In the axial direction, the rotating shaft is in sliding connection with the housing. The position of the housing in the refrigerant pump is fixed, the housing defines the movement space of the gear part, and the rotating shaft is in sliding connection with the housing and the gear part, thereby avoiding the wear and tear caused by the movement of the rotating shaft, the housing and the gear part in the axial direction.

[0018] In one possible implementation, the first gear pump head and the second gear pump head are arranged in series, the refrigerant pump comprises a shell and first and second partition walls located in the shell, the first and second partition walls partition the shell to form first, second and third cavities, the first gear pump head is located in the first cavity, the rotor is located in the second cavity, and the second gear pump head is located in the third cavity. Refrigerant input into the refrigerant pump sequentially passes through the first cavity, the first gear pump head, the second cavity, the second gear pump head and the third cavity and is output from the refrigerant pump. In other words, the series arrangement means that the internal space of the first gear pump head is in communication with the internal space of the second gear pump head, so that the refrigerant can sequentially pass through the first and second gear pump heads to achieve transmission and pressurization of the refrigerant.

[0019] When the first gear pump head and the second gear pump head are arranged in series, the flow rate of the first gear pump head is the same as that of the second gear pump head. For example, if the flow rate of the first gear pump head is greater than that of the second gear pump head, the refrigerant passing through the first gear pump head cannot enter the second gear pump head in time and be discharged, which causes more and more refrigerant passing through the first gear pump head to accumulate in the space between the first and second gear pump heads, and the space between the first and second gear pump heads is limited. If the flow rate of the second gear pump head is greater than that of the first gear pump head, the refrigerant passing through the first gear pump head cannot meet the flow rate requirement of the second gear pump head, which affects the normal operation of the refrigerant pump. It should be noted that the flow rate of the first gear pump head is not strictly required to be exactly the same as that of the second gear pump head. When the flow rate of the first gear pump head is close to that of the second gear pump head, the second cavity can be used for adjustment, and the normal operation of the refrigerant pump can also be achieved.

[0020] When the first gear pump head and the second gear pump head are arranged in series, the sum of the head of the first gear pump head and the head of the second gear pump head is equal to the required head of the refrigerant pump. That is, the series arrangement of the first and second gear pump heads can achieve head sharing. In the case where the required head of the refrigerant pump is unchanged, when only the first gear pump head is present, the head of the first gear pump head is the head of the refrigerant pump. In the present embodiment, when the first and second gear pump heads are present and arranged in series, the head of the first gear pump head is half of the head of the refrigerant pump, and the head of the second gear pump head is also half of the head of the refrigerant pump. The head of each gear pump head is reduced by half, which can effectively improve the service life of the gear pump head and the reliability of the refrigerant pump. The first and second gear pump heads are arranged in series, so that the refrigerant passing through the first gear pump head is pressurized and then passes through the second gear pump head to achieve secondary pressurization, so as to achieve the required head of the refrigerant pump.

[0021] In a possible implementation, the refrigerant pump comprises an input port and an output port, the first gear pump head comprises a first inlet and a first outlet, the second gear pump head comprises a second inlet and a second outlet, the first inlet is communicated with the input port, the second outlet is communicated with the output port, and the first outlet is communicated with the second inlet. The refrigerant pump is provided with an input port and an output port for transmitting refrigerant. The first outlet of the first gear pump head is communicated with the second inlet of the second gear pump head, so that the outflowing refrigerant from the first outlet of the first gear pump head enters the second gear pump head through the second inlet, that is, the first gear pump head and the second gear pump head are connected in series, the lift can be shared, and the service life and reliability of the refrigerant pump are improved.

[0022] In a possible implementation, the first gear pump and the second gear pump are connected in parallel, refrigerant input into the refrigerant pump enters the first gear pump head and the second gear pump head respectively and is output from the refrigerant pump. When the first gear pump head and the second gear pump head are connected in parallel, the lift of the first gear pump head is the same as the lift of the second gear pump head, and both are the same as the required lift of the refrigerant pump. When the first gear pump head and the second gear pump head are connected in parallel, the sum of the flow of the first gear pump head and the flow of the second gear pump head is equal to the flow of the required refrigerant pump. That is, the first gear pump head and the second gear pump head connected in parallel can realize flow sharing. In the case that the flow of the required refrigerant pump is unchanged, when only the first gear pump head is provided, or when the first gear pump head and the second gear pump head are connected in series, the flow of the first gear pump head is the flow of the refrigerant pump, and when the first gear pump head and the second gear pump head are connected in parallel, the flow of the first gear pump head is half of the flow of the refrigerant pump, and the flow of the second gear pump head is also half of the flow of the refrigerant pump. The flow of each gear pump head is reduced by half, so the rotating speed of the shaft, the first gear pump head and the second gear pump head is also reduced to half of the original rotating speed, which can effectively improve the service life of the gear pump head and the reliability of the refrigerant pump.

[0023] In a possible implementation, the refrigerant pump comprises a first input port, a second input port and an output port, the first gear pump head comprises a first inlet and a first outlet, the second gear pump head comprises a second inlet and a second outlet, the first inlet is communicated with the first input port, the second inlet is communicated with the second input port, and the first outlet and the second outlet are both communicated with the output port. When connected in parallel, the refrigerant pump is provided with two input ports, i.e., the first input port and the second input port, and one output port for transmitting refrigerant. The first outlet and the second outlet are both communicated with the output port of the refrigerant pump, so that the refrigerant flowing out of the first outlet of the first gear pump head cannot enter the second gear pump head, and the refrigerant flowing out of the second outlet of the second gear pump head cannot enter the first gear pump head, i.e., the first gear pump head and the second gear pump head are connected in parallel, the flow can be shared, and the service life and reliability of the refrigerant pump can be improved.

[0024] In a possible implementation, the first gear pump head comprises a first inlet, and the first inlet is located at a bottom region of the first gear pump head, or the second gear pump head comprises a second inlet, and the second inlet is located at a bottom region of the second gear pump head. The refrigerant pump can be placed horizontally, vertically or in other conditions. The horizontal placement can be understood as that the axial direction of the rotating shaft is perpendicular to the direction of gravity, and the vertical placement can be understood as that the axial direction of the rotating shaft is parallel to the direction of gravity. Regardless of the horizontal placement or the vertical placement, the first inlet is arranged at the bottom region of the first gear pump head, and the second inlet is arranged at the bottom region of the second gear pump head, which is beneficial to avoiding the cavitation problem and the influence of bubbles on the flow of the refrigerant pump. Specifically, the refrigerant entering the input port of the refrigerant pump can contain bubbles. The bubbles entering the first gear pump head can cause cavitation, and can cause the refrigerant pump to fail and cause the flow of the pump head to be greatly attenuated. The first inlet is arranged at the bottom region of the first gear pump head, so that even if there are bubbles in the region between the input port of the refrigerant pump and the first inlet of the first gear pump head, the bubbles will rise and gather at the top, and the liquid refrigerant will be at the bottom and enter the first gear pump head through the first inlet located at the bottom region, thereby avoiding the influence of the bubbles on the first gear pump head. After the refrigerant flows out of the first gear pump head, it can be partially vaporized to form bubbles due to the heat generated by the motor in the second cavity. The second inlet is arranged at the bottom region of the second gear pump head, so that even if there are bubbles in the second cavity, the bubbles will rise and gather at the top, and the liquid refrigerant will be at the bottom and enter the second gear pump head through the second inlet located at the bottom region, thereby avoiding the influence of the bubbles on the second gear pump head.

[0025] It should be noted that the bottom region is not strictly limited to the bottom. In the case where a structure comprises a top portion, a bottom portion and a middle portion located between the top portion and the bottom portion, the bottom region can be understood as a region between the middle portion and the bottom portion and adjacent to the bottom portion.

[0026] In other embodiments, the first inlet and the second inlet can also not be arranged at the bottom region in application environments where bubbles have little effect or are not prone to be generated, and can be arranged according to requirements. The present application does not limit this.

[0027] In a possible implementation, the volume between the second partition wall and the rotor is greater than the volume between the first partition wall and the rotor. The motor generates heat during operation. After the refrigerant flows out of the first gear pump head and enters the second cavity, the liquid refrigerant part is affected by the heat generated by the motor and gasifies to generate bubbles. In this embodiment, the volume between the second partition wall and the rotor is greater than the volume between the first partition wall and the rotor, so that there is enough space for the refrigerant (here, the storage cannot be understood as stable and unchanging. The refrigerant in the area between the second partition wall and the rotor is always in a flowing state. The refrigerant flowing out of the first gear pump head continuously enters the area between the second partition wall and the rotor. The refrigerant entering the area between the second partition wall and the rotor also continuously enters the second gear pump head) to store liquid refrigerant, that is, a liquid storage space. Even if the liquid refrigerant part gasifies to generate bubbles due to the influence of the heat generated by the motor, the bubbles have enough time to rise and gather at the top. A large amount of liquid refrigerant is at the bottom and enters the second gear pump head through the second inlet located at the bottom region, thereby avoiding the influence of the bubbles on the second gear pump head and facilitating the improvement of the service life of the refrigerant pump.

[0028] In a possible implementation, the refrigerant pump comprises a first bearing and a second bearing. The first bearing is located between the first gear pump head and the rotor and is sleeved on the rotating shaft. The second bearing is located between the second gear pump head and the rotor and is sleeved on the rotating shaft. The first bearing and the second bearing support the rotating shaft, can reduce the friction coefficient during the movement of the rotating shaft, ensure the rotation accuracy of the rotating shaft, and realize the rotation of the rotating shaft through the cooperation of the second bearing and the first bearing.

[0029] In a possible implementation, the refrigerant pump comprises a baffle. The baffle is located between the rotor and the second partition wall and is close to the rotor. The baffle can be a heat insulation plate. The baffle is used to block the heat generated by the motor from entering the area between the second partition wall and the rotor, reduce the influence of the heat generated by the motor on the refrigerant in the area between the second partition wall and the rotor, reduce the generation of bubbles, prevent the continuous gasification of the refrigerant, effectively avoid the cavitation problem and the influence of the bubbles on the flow of the second gear pump head, and improve the service life of the refrigerant pump.

[0030] In a possible implementation, the number of the first gear pump heads is at least two, the internal spaces of the at least two first gear pump heads are communicated, and the gear portions of the at least two first gear pump heads are spaced apart and are sleeved on the rotating shaft. Correspondingly, the number of the second gear pump heads is at least two, and the number of the second gear pump heads is consistent with that of the first gear pump heads, so as to balance the force received by the rotating shaft and avoid the wear problem caused by the inclination of the rotating shaft. The internal spaces of the at least two first gear pump heads are communicated to achieve series connection, so that the lift of the refrigerant pump can be shared, and the reliability and service life of the refrigerant pump can be improved. In other implementations, the at least two first gear pump heads can also be connected in parallel to share the flow.

[0031] In a second aspect, the application provides a refrigeration system. The refrigeration system can be an air conditioning system, and the refrigeration system comprises an evaporator, a condenser, a compressor, a first one-way valve, a second one-way valve, and the refrigerant pump in any of the foregoing implementations. The first one-way valve is connected in parallel with the refrigerant pump, and the second one-way valve is connected in parallel with the compressor. The compressor, the condenser, the refrigerant pump, and the evaporator are connected to form a loop. Specifically, the evaporator comprises a first input end and a first output end, the condenser comprises a second input end and a second output end, the compressor is connected between the first output end and the second input end, and the refrigerant pump is connected between the second output end and the first input end. The compressor provides power for the circulation of the refrigerant and increases the temperature of the refrigerant in the compression process, so as to facilitate the dissipation of the heat absorbed by the refrigerant to the outdoor. However, the compressor consumes a large amount of power. In the application, the refrigerant pump and the compressor are connected in parallel. When the outdoor temperature is low, the refrigeration system does not need to be compressed to achieve heat dissipation. At this time, it is not economical to use the compressor. A refrigerant pump can be connected in parallel in the system to provide power at low temperature. The power consumption of the refrigeration system can be greatly reduced.

[0032] The first gear pump head and the second gear pump head in the refrigerant pump are symmetrically arranged on both sides of the rotor, so that the wear problem caused by the eccentricity of the shaft can be avoided. When the first gear pump head and the second gear pump head are connected in series, the lift can be shared, and the service life of the refrigerant pump can be significantly improved. When the first gear pump head and the second gear pump head are connected in parallel, the flow can be shared, and the service life of the refrigerant pump can be improved. The first gear portion of the first gear pump head is in sliding connection with the rotating shaft, and the second gear portion of the second gear pump head is in sliding connection with the rotating shaft, so that the wear problem caused by the shaft excursion can be avoided. When the first gear pump head and the second gear pump head are connected in series, the second cavity is arranged, which is beneficial to balance the flow of the first gear pump head and the second gear pump head. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background, the drawings needed to be used in the embodiments of the present application or the background will be described below.

[0034] Figure 1 is a structural schematic diagram of a refrigerant pump provided by an embodiment of the present application;

[0035] Figure 2 is a structural schematic diagram of a refrigerant pump provided by an embodiment of the present application;

[0036] Figure 3 is a structural schematic diagram of a first gear pump head provided by an embodiment of the present application;

[0037] Figure 4 is a structural schematic diagram of a refrigerant pump provided by an embodiment of the present application;

[0038] Figure 5 is a structural schematic diagram of a first gear pump head provided by another embodiment of the present application;

[0039] Figure 6 is a structural schematic diagram of a first gear pump head provided by another embodiment of the present application;

[0040] Figure 7 is a structural schematic diagram of a refrigerant pump provided by another embodiment of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without any creative work fall within the scope of protection of the present application.

[0042] The refrigeration system of the present application can be an air conditioning system, specifically, a precision air conditioning system. The precision air conditioning system is an air conditioner capable of precisely adjusting temperature and humidity, which is consistent with the principle of ordinary civilian air conditioners, but has more precise temperature and humidity control and large refrigerating capacity. The precision air conditioning system can be applied in environments such as data centers, which need to be continuously operated without interruption throughout the year and have high reliability requirements.

[0043] As shown in Figure 1 Figure 1 ​is a structural schematic diagram of the refrigeration system 100. The refrigeration system 100 comprises an evaporator 10, a compressor 20, a condenser 30, a liquid accumulator 40, a refrigerant pump 50, a first one-way valve 60 and a second one-way valve 70. The evaporator 10 is located indoors, and the condenser 30 is located outdoors. The evaporator 10 is used to absorb heat, and the condenser 30 is used to release heat. The compressor 20, the condenser 30, the refrigerant pump 50 and the evaporator 10 are connected to form a loop. Specifically, the evaporator 10 comprises a first input end 11 and a first output end 12, and the condenser 30 comprises a second input end 31 and a second output end 32. A pipeline between the first output end 12 and the second input end 31 is a gaseous pipeline for conveying gas, and a pipeline between the second output end 32 and the first input end 11 is a liquid pipeline for conveying liquid. Because the liquid is incompressible and the compressor 20 can only compress gas, the compressor 20 can only be arranged between the gaseous pipeline between the first output end 12 and the second input end 31. Because the refrigerant pump 50 can only transport liquid, the refrigerant pump 50 can only be arranged between the liquid pipeline between the second output end 32 and the first input end 11 outdoors. The liquid accumulator 40 is used to store liquid, and the liquid accumulator 40 is arranged between the second output end 32 and the refrigerant pump 50. The first one-way valve 60 is connected in parallel with the refrigerant pump 50, and the second one-way valve 70 is connected in parallel with the compressor 20.

[0044] The refrigeration system 100 operates in two paths. One path is the path of the compressor 20: the liquid refrigerant in the evaporator 10 indoors absorbs heat indoors and vaporizes into a gaseous state. The gaseous refrigerant is transmitted to the compressor 20. The compressor 20 provides power for the gaseous refrigerant cycle, and the temperature of the gaseous refrigerant is increased in the compression process, so that the heat absorbed by the gaseous refrigerant can be released to the outdoors, i.e., the gas before entering the compressor 20 is a medium-temperature gas, and the gas compressed by the compressor 20 is a high-temperature gas. Understandably, when the outdoor temperature is high, it is difficult to release the heat of the gaseous refrigerant to the outdoors. The compressor 20 increases the temperature of the gaseous refrigerant in the compression process, so that the temperature of the gaseous refrigerant is higher than the outdoor temperature, and the heat absorbed by the gaseous refrigerant can be released to the outdoors. The gaseous refrigerant compressed by the compressor 20 is liquefied into a liquid state when passing through the condenser 30 outdoors, releases heat, and then the low-temperature liquid refrigerant enters the liquid accumulator 40 and is transmitted to the evaporator 10 through the first one-way valve 60, realizing the cycle of heat dissipation. The other path is the path of the refrigerant pump 50: the liquid refrigerant in the evaporator 10 indoors absorbs heat indoors and vaporizes into a gaseous state. The gaseous refrigerant is transmitted to the condenser 30 outdoors through the second one-way valve 70 and is liquefied into a liquid state, releasing heat. Then the low-temperature liquid refrigerant enters the liquid accumulator 40 and is transmitted to the refrigerant pump 50. The refrigerant pump 50 provides power for the refrigerant cycle. The liquid refrigerant pressurized by the refrigerant pump 50 continues to be transmitted to the evaporator 10, realizing the cycle of heat dissipation.

[0045] In this embodiment, the function of the first check valve 60 and the second check valve 70 is to switch the path of the compressor 20 and the path of the refrigerant pump 50. When the outlet pressure of the check valve is greater than the inlet pressure, it cannot be opened. Therefore, when the refrigerant pump 50 is running, the first check valve 60 cannot be opened and the second check valve 70 is opened. When the compressor 20 is running, the first check valve 60 is opened and the second check valve 70 cannot be opened, so as to realize the switching of the pipeline.

[0046] When the outdoor temperature is high, compressor 20 is needed to raise the temperature of the gaseous refrigerant. This allows the heat from the gaseous refrigerant to be released outdoors, but compressor 20 consumes a lot of electricity. When the outdoor temperature is low, the refrigeration system 100 can dissipate heat without compressor 20. In this case, using compressor 20 is very uneconomical. Power can be provided by a low-power refrigerant pump 50 connected in parallel with the refrigeration system 100, significantly reducing the energy consumption of the refrigeration system 100. Therefore, providing a high-performance refrigerant pump 50 is crucial for the refrigeration system 100.

[0047] It should be noted that the above-mentioned refrigeration system 100 is only one implementation of the refrigeration system, and the refrigerant pump 50 of this application can also be used in other refrigeration systems.

[0048] like Figure 2 and Figure 3 As shown, Figure 2 This is a schematic diagram of the refrigerant pump 50. Figure 3 This is a schematic diagram of the structure of the first gear pump head 52. The refrigerant pump 50 is used to transfer refrigerant and provide power to the refrigerant. The refrigerant pump 50 includes a housing 51, a first gear pump head 52, a second gear pump head 53, a power unit 54, a first bearing 55, and a second bearing 56. The first gear pump head 52, the second gear pump head 53, the power unit 54, the first bearing 55, and the second bearing 56 are all located inside the housing 51. Compared to an externally located power unit 54, the fact that the power unit 54 is built into the housing 51 in this application gives the refrigerant pump 50 the advantages of good sealing, high reliability, simple structure, and small size. In this application, the first gear pump head 52, the power unit 54, and the second gear pump head 53 are arranged sequentially.

[0049] The shell 51 comprises an input port 511 and an output port 512, the refrigerant enters the inside of the shell 51 through the input port 511, and is outputted through the output port 512 after being transmitted and pressurized. The shell 51 has high strength and good sealing property, and protects and seals the first gear pump head 52, the second gear pump head 53, the power part 54, the first bearing 55 and the second bearing 56 inside. The shell 51 is provided with a first isolation wall 57 and a second isolation wall 58, the first isolation wall 57 and the second isolation wall 58 isolate the inside space of the shell 51 to form a first cavity 516, a second cavity 517 and a third cavity 518, the first gear pump head 52 is located in the first cavity 516, the rotor 542 is located in the second cavity 517, and the second gear pump head 53 is located in the third cavity 518.

[0050] The first gear pump head 52 comprises a first shell 521 and a first gear part 522, and the first gear part 522 is located in the first shell 521. The first shell 521 is fixed in the shell 51, and is provided with a first inlet 5211 and a first outlet 5212. The first gear part 522 comprises a first gear 5221 and a second gear 5222, the first gear 5221 comprises a first connecting part 5223 and a first tooth part 5224 surrounding the first connecting part 5223, and the second gear 5222 comprises a second connecting part 5225 and a second tooth part 5226 surrounding the second connecting part 5225. The first tooth part 5224 is engaged with the second tooth part 5226.

[0051] The second gear pump head 53 comprises a second shell 531 and a second gear part 532, and the second gear part 532 is located in the second shell 531. The second shell 531 is fixed in the shell 51, and comprises a second inlet 5311 and a second outlet 5312. The structure of the second gear part 532 is the same as that of the first gear part 522, which will not be described here.

[0052] The power part 54 is generally an electric motor, which comprises a rotating shaft 541, a rotor 542 and a stator 543. The rotating shaft 541 comprises a main shaft 5411 and first and second end portions 5412 and 5413 located on both sides of the main shaft 5411. The main shaft 5411 is located in the middle of the rotating shaft 541. It should be noted that the middle here does not mean the geometric center of the rotating shaft 541, but any portion between the first and second end portions 5412 and 5413 can be understood as the main shaft 5411 in the middle. The rotor 542 is fixedly connected to the main shaft 5411, and the stator 543 is fixedly connected to the shell 51 and surrounds the rotor 542. The surrounding here means that the stator 543 is provided with a through hole, and the rotor 542 is located in the through hole of the stator 543. The first end portion 5412 is inserted into the first gear part 522, and the second end portion 5413 is inserted into the second gear part 532. In other words, in the axial direction A1 of the rotating shaft 541, the first gear part 522, the rotor 542 and the second gear part 532 are sequentially and spaced arranged and all surround the rotating shaft 541. The surrounding here means that the first gear part 522, the rotor 542 and the second gear part 532 are all provided with a through hole, and the rotating shaft 541 passes through the through holes of the first gear part 522, the rotor 542 and the second gear part 532, that is, the first gear part 522, the rotor 542 and the second gear part 532 are all surrounded by the rotating shaft 541.

[0053] The stator 543 is provided with a coil, and the stator 543 generates a rotating geomagnetic field when powered. The magnetic field generated by the stator 543 interacts with the magnetic field generated by the rotor 542, thereby driving the rotor 542 to rotate. The rotor 542 drives the rotating shaft 541 to rotate, and the rotating shaft 541 can drive the first gear part 522 and the second gear part 532 to rotate. The refrigerant is transmitted and pressurized when passing through the first gear part 522 and the second gear part 532 in sequence.

[0054] The first bearing 55 is located between the first gear pump head 52 and the rotor 542 and surrounds the rotating shaft 541, and the second bearing 56 is located between the second gear pump head 53 and the rotor 542 and surrounds the rotating shaft 541. Specifically, the refrigerant pump 50 is provided with first and second isolation walls 57 and 58. The first and second isolation walls 57 and 58 are fixed to the inner surface of the shell 51 and are both provided with a mounting through hole. The first bearing 55 is mounted to the mounting through hole of the first isolation wall 57, and the second bearing 56 is mounted to the mounting through hole of the second isolation wall 58. The rotating shaft 541 passes through the first and second bearings 55 and 56, and the first and second bearings 55 and 56 support the rotating shaft 541, which can reduce the friction coefficient during the movement of the rotating shaft 541 and ensure the rotation accuracy of the rotating shaft 541.

[0055] The first gear pump head 52 and the second gear pump head 53 are symmetrically arranged relative to the rotor 542 in the present application. The symmetry here does not strictly limit the distance between the first gear pump head 52 and the rotor 542 to be equal to the distance between the second gear pump head 53 and the rotor 542. In the specific arrangement process, the distance between the first gear pump head 52 and the rotor 542 can also be different from the distance between the second gear pump head 53 and the rotor 542. As long as the first gear pump head 52 and the second gear pump head 53 are located at opposite ends of the rotor 542 in the axial direction A1, they can be understood as being arranged oppositely.

[0056] The first gear pump head 52 and the second gear pump head 53 rely on the change and movement of the working volume formed between the pump cylinder and the meshing gears to transport or pressurize the liquid. Due to the continuous meshing of the gears, the refrigerant is mechanically squeezed out, the pressure change of the gear pump head is small, and cavitation is not easy to occur. Cavitation is a failure mode of the pump. The liquid medium vaporizes to form bubbles at the pump inlet due to excessive pressure reduction. The bubbles condense into liquid at the pump outlet due to pressure rise. The formation and disappearance of bubbles can produce a huge point burst pressure, causing pitting on the metal surface of the pump head, which is the cavitation problem. Long-term cavitation can affect the reliability of the refrigerant pump and reduce the service life of the refrigerant pump. In addition, the bubbles gathered in the pump head can also cause a significant decrease in pump head flow, failing to meet the preset requirements. The first gear pump head 52 and the second gear pump head 53 of the present application do not rely on pressure changes to transport and pressurize the refrigerant. The overall pressure change is small, and there is almost no cavitation problem.

[0057] The gear pump head is an eccentric structure, and the shaft 541 is prone to wear and tear during operation due to unbalanced stress, which reduces the service life of the refrigerant pump 50. The gear pump head includes an external meshing pump head and an internal meshing pump head. Taking the internal meshing pump head as an example, the first gear 5221 is an internal gear, the second gear 5222 is an external gear, the second gear 5222 is sleeved on the periphery of the first gear 5221 and meshes with the first gear 5221, the first gear 5221 is connected with the shaft 541, and the shaft 541 can drive the first gear 5221 to rotate, and the first gear 5221 drives the second gear 5222 to rotate, so as to realize the normal operation of the refrigerant pump 50. The center of the first gear 5221 coincides with the axis of the shaft 541, and the center of the second gear 5222 does not coincide with the axis of the shaft 541. With the rotation of the shaft 541, the relative position of the center of the second gear 5222 and the axis of the shaft 541 is constantly changing, resulting in an eccentric structure of the gear pump head. In the prior art, when the gear pump head is arranged only at one end of the rotor, that is, only the first gear type pump head 52 is included, the shaft 541 is unbalanced during operation, which can cause tilting, causing the first bearing 55 and the second bearing 56 connected with the shaft 541 to have serious wear and tear, reducing the reliability of the refrigerant pump 50.

[0058] The application can balance the force received by the two ends of the rotating shaft 541 by arranging the first gear pump head 52 and the second gear pump head 53 at the two ends of the rotating shaft 542, avoid the wear of the first bearing 55 and the second bearing 56 caused by the inclination of the rotating shaft 541 due to the eccentricity of the shaft, improve the reliability and service life of the refrigerant pump 50, and thus improve the quality and application value of the refrigerant pump 50. The refrigerant pump 50 has a simple structure and low cost.

[0059] The first gear pump head 52 and the second gear pump head 53 can be arranged in series or in parallel. The series arrangement means that the refrigerant passing through the first gear pump head 52 also passes through the second gear pump head 53. The parallel arrangement means that the refrigerant passing through the first gear pump head 52 does not pass through the second gear pump head 53, and the refrigerant passing through the second gear pump head 53 does not pass through the first gear pump head 52.

[0060] First, referring to Figure 2 The first gear pump head 52 and the second gear pump head 53 are arranged in series. It should be noted that the structures of the first gear pump head 52 and the second gear pump head 53 can be the same or different, as long as the flow rates of the first gear pump head 52 and the second gear pump head 53 are the same. Specifically, the first inlet 5211 is communicated with the input port 511, the second outlet 5312 is communicated with the output port 512, and the first outlet 5212 is communicated with the second inlet 5311, so as to realize the series arrangement of the first gear pump head 52 and the second gear pump head 53. That is, the internal space of the first gear pump head 52 is communicated with the internal space of the second gear pump head 53. In this way, the refrigerant enters the housing 51 through the input port 511, enters the first housing 521 through the first inlet 5211, is pressurized by the first gear part 522, and is discharged through the first outlet 5212 and enters the second cavity 517. The refrigerant passing through the first gear pump head 52 continues to enter the second housing 531 through the second inlet 5311, is pressurized again by the second gear part 532, is discharged from the second gear pump head 53 through the second outlet 5312, and is discharged from the refrigerant pump 50 through the output port 512, so as to realize transmission and pressurization. In other words, the refrigerant entering the refrigerant pump 50 passes through the first cavity 516, the first gear pump head 52, the second cavity 517, the second gear pump head 53, and the third cavity 518 in sequence and is output from the refrigerant pump 50.

[0061] When the first gear pump head 52 and the second gear pump head 53 are arranged in series, the flow rate of the first gear pump head 52 is the same as that of the second gear pump head 53. For example, if the flow rate of the first gear pump head 52 is greater than that of the second gear pump head 53, the refrigerant passing through the first gear pump head 52 cannot enter the second gear pump head 53 in time, which will cause more and more refrigerant passing through the first gear pump head 52 to accumulate in the second cavity 517. Since the space of the second cavity 517 is limited, when the second cavity 517 is filled with refrigerant, the refrigerant pump 50 will fail. If the flow rate of the second gear pump head 53 is greater than that of the first gear pump head 52, the refrigerant passing through the first gear pump head 52 cannot meet the flow rate requirement of the second gear pump head 53, which will cause the first gear pump head 52 to supply less refrigerant than required by the second gear pump head 53, the refrigerant between the first gear pump head 52 and the second gear pump head 53 is exhausted, and the refrigerant pump 50 fails.

[0062] It should be noted that the flow rate of the first gear pump head 52 and the flow rate of the second gear pump head 53 in the present application are not strictly required to be exactly the same. When the flow rate of the first gear pump head 52 and the flow rate of the second gear pump head 53 are close to each other, the second cavity 517 can be adjusted to achieve normal operation of the refrigerant pump 50.

[0063] When the first gear pump head 52 and the second gear pump head 53 are arranged in series, the sum of the head of the first gear pump head 52 and the head of the second gear pump head 53 is equal to the required head of the refrigerant pump 50. That is, the first gear pump head 52 and the second gear pump head 53 arranged in series can achieve head sharing. In the case where the required head of the refrigerant pump 50 is unchanged, when only the first gear pump head 52 is present, the head of the first gear pump head 52 is the head of the refrigerant pump 50. In the present embodiment, the first gear pump head 52 and the second gear pump head 53 are arranged in series in the refrigerant pump 50, the head of the first gear pump head 52 is half of the head of the refrigerant pump 50, and the head of the second gear pump head 53 is also half of the head of the refrigerant pump 50. The head of each gear pump head is reduced by half, which can effectively improve the service life of the gear pump head and improve the reliability of the refrigerant pump 50. The first gear pump head 52 and the second gear pump head 53 are arranged in series, so that the refrigerant passing through the first gear pump head 52 is pressurized, and then passes through the second gear pump head 53 to achieve secondary pressurization, so as to achieve the required head of the refrigerant pump 50.

[0064] The number of the first gear pump heads 52 can be one, two, three, four, or five, and so on, and the number of the second gear pump heads 53 can be one, two, three, four, or five, and so on, and the number of the second gear pump heads 53 is consistent with the number of the first gear pump heads 52, so as to balance the force on the rotating shaft 541 and avoid the wear problem caused by the inclination of the rotating shaft 541. When the number of the first gear pump heads 52 is at least two, the internal spaces of the at least two first gear pump heads 52 are communicated to realize series connection, and the first gear parts of the at least two first gear pump heads 52 are arranged at intervals and are sleeved on the rotating shaft 541, so that the lift of the refrigerant pump 50 can be shared, and the reliability and service life of the refrigerant pump 50 can be improved. Correspondingly, when the number of the second gear pump heads 53 is at least two, the internal spaces of the at least two second gear pump heads 53 are communicated to realize series connection, and the at least two first gear pump heads 52 are connected in series and the at least two second gear pump heads 53 are connected in series, and the more gear pump heads are connected in series, the better the lift of the refrigerant pump 50 can be shared. In other embodiments, the at least two first gear pump heads 52 can be connected in parallel, and the at least two second gear pump heads 53 can also be connected in parallel.

[0065] The space between the first partition wall 57 and the second partition wall 58 is the second cavity 517, which includes a first sub-cavity 5171 between the first partition wall 57 and the rotor 542 and a second sub-cavity 5172 between the second partition wall 58 and the rotor 542. The second cavity 517 is used to store refrigerant, so as to balance the flow of the first gear pump heads 52 and the second gear pump heads 53, so that when the flow of the first gear pump heads 52 and the flow of the second gear pump heads 53 are close, the second cavity 517 can play a buffering and adjusting role to ensure the normal operation of the refrigerant pump 50. It should be noted that the storage here cannot be understood as stable and unchanging, and the refrigerant in the second cavity 517 is always in a flowing state, the refrigerant flowing out of the first gear pump heads 52 enters the second cavity 517 continuously, and the refrigerant entering the second cavity 517 also enters the second gear pump heads 53 continuously.

[0066] In one specific embodiment, the volume between the second partition wall 58 and the rotor 542 is greater than the volume between the first partition wall 57 and the rotor 542, i.e. the volume of the second sub-cavity 5172 is greater than the volume of the first sub-cavity 5171. The refrigerant entering the second inlet 5311 of the second gear pump head 53 must all be stable liquid refrigerant, if there is gaseous refrigerant at the second inlet 5311, cavitation will occur, which will also cause the refrigerant pump 50 to malfunction or have no flow. The motor generates heat during operation, and after the refrigerant flows out of the first gear pump head 52 and enters the second cavity 517, it is affected by the heat generated by the motor, and part of the liquid refrigerant will vaporize to produce bubbles. The present embodiment sets the volume of the second sub-cavity 5172 to be greater than the volume of the first sub-cavity 5171, so that the second sub-cavity 5172 is large enough, so that most of the refrigerant flowing out of the first gear pump head 52 is stored in the second sub-cavity 5172, even if affected by the heat generated by the motor, part of the liquid refrigerant vaporizes to produce bubbles, the bubbles will have enough time to rise and gather at the top, and a large amount of liquid refrigerant is at the bottom of the second sub-cavity 5172 and enters the second gear pump head 53 through the second inlet 5311 located at the bottom area, avoiding the case where the second sub-cavity 5172 is small, the bubbles produced will enter the second gear pump head 53 in a short period of time, causing cavitation, affecting the service life of the refrigerant pump 50.

[0067] A baffle 593 is arranged in the second sub-cavity 5172, and the baffle 593 is used to block the heat generated by the motor during operation from entering the second sub-cavity 5172. That is, the baffle 593 is located between the rotor 542 and the second partition wall 58, and the baffle 593 is arranged close to the rotor 542, the baffle 593 is fixed to the inner surface of the shell 51, and the baffle 593 is a heat insulation plate. The heat generated by the stator 543 and the rotor 542 during operation can be blocked by the baffle 593, reducing the influence of the heat generated by the motor on the refrigerant in the second sub-cavity 5172, reducing the generation of bubbles, preventing the continuous vaporization of the refrigerant in the second sub-cavity 5172, effectively avoiding the cavitation problem and the influence of bubbles on the flow of the second gear pump head 53, and improving the service life of the refrigerant pump 50.

[0068] The refrigerant pump 50 of the present application can be horizontally placed, vertically placed or placed in other ways. The horizontal placement can be understood as the axial direction A1 of the rotating shaft 542 being perpendicular to the direction of gravity A2, and the vertical placement can be understood as the axial direction A1 of the rotating shaft 542 being parallel to the direction of gravity A2. Whether it is horizontally placed or vertically placed, the first inlet 5211 is arranged at the bottom region 5213 of the first gear pump head 52, and the second inlet 5311 is arranged at the bottom region 5313 of the second gear pump head 53. It should be noted that the bottom region here is not strictly limited to the bottom. In the case where a structural member includes a top portion and a bottom portion arranged opposite to each other, and a middle portion between the top portion and the bottom portion, the bottom region can be understood as a region between the middle portion and the bottom portion and adjacent to the bottom portion.

[0069] Taking the horizontal placement as an example, the refrigerant entering the input port 511 of the refrigerant pump 50 can have bubbles. The bubbles entering the first gear pump head 52 can cause cavitation, which can cause the refrigerant pump 50 to malfunction and cause the flow of the pump head to be greatly attenuated. In the present embodiment, the first inlet 5211 is arranged at the bottom region 5213 of the first gear pump head 52. In this way, even if there are bubbles in the region between the input port 511 and the first inlet 5211, the bubbles will rise and gather at the top, while the liquid refrigerant will be at the bottom and enter the first gear pump head 52 through the first inlet 5211 arranged at the bottom region 5213, thereby avoiding the influence of the bubbles on the first gear pump head 52. If the first inlet 5211 is arranged at the top region of the first gear pump head 52, the bubbles gathered at the top region will be easy to enter the first gear pump head 52 through the first inlet 5211, causing cavitation problems. After the refrigerant flows out of the first outlet 5212 of the first gear pump head 52, it can be partially vaporized to form bubbles due to the heat generated by the motor in the second cavity 517. The second inlet 5311 is arranged at the bottom region 5313 of the second gear pump head 53. In this way, even if there are bubbles in the second cavity 517, the bubbles will rise and gather at the top, while the liquid refrigerant will be at the bottom and enter the second gear pump head 53 through the second inlet 5311 arranged at the bottom region 5313, thereby avoiding the influence of the bubbles on the second gear pump head 53.

[0070] It should be noted that in the specific design process, only the first inlet 5211 can be arranged at the bottom region 5213 of the first gear pump head 52, and the second inlet 5311 can not be arranged at the bottom region 5313 of the second gear pump head 53, or only the first inlet 5211 can not be arranged at the bottom region 5213 of the first gear pump head 52, and the second inlet 5311 can be arranged at the bottom region 5313 of the second gear pump head 53, or the first inlet 5211 can be arranged at the bottom region 5213 of the first gear pump head 52, and the second inlet 5311 can be arranged at the bottom region 5313 of the second gear pump head 53, and the present application does not limit this.

[0071] In other embodiments, in the application environment where the bubbles have little effect or are not easy to generate, the first inlet 5211 and the second inlet 5311 can also not be arranged at the bottom region, and can be arranged according to requirements, which is not limited in the application.

[0072] For reference Figure 2 、 Figure 3 and Figure 4 , Figure 4 is a schematic view of a partial structure of the refrigerant pump 50. In one specific embodiment, in the axial direction A1, the first gear part 522 is in sliding connection with the rotating shaft 541, and the first housing 521 is in sliding connection with the rotating shaft 541. Specifically, the first connecting part 5223 is provided with a rectangular through hole 5227, and the first end part 5412 and the second end part 5413 are provided with rectangular blocks, which pass through the rectangular through hole 5227, so that the rotating shaft 541 can drive the first gear 5221 to rotate, and the first gear 5221 can drive the second gear 5222 to rotate.

[0073] The rotor 542 of the motor is correspondingly arranged with the stator 543. In the actual assembly process, the position of the rotor 542 in the axial direction A1 may deviate, and in the process of motor operation, the rotor 542 will automatically adjust to the preset position. When the first gear part 522 is fixedly connected with the rotating shaft 541, in the process of automatic adjustment of the rotor 542, the rotor 542 will drive the rotating shaft 541 to move, the rotating shaft 541 will drive the first gear 5221 to move, and the first gear 5221 will hit the first housing 521 of the first gear pump head 52, aggravate the friction, and cause the first gear 5221 and the first housing 521 to be severely worn. When the rotating shaft 541 drives the first gear 5221 to move, the first gear 5221 and the second gear 5222 are misaligned, and refrigerant leakage problem is easy to occur. In the embodiment, the first gear 5221 is in sliding connection with the rotating shaft 541, so that in the process of the rotor 542 driving the rotating shaft 541 to move, the rotating shaft 541 and the first gear 5221 slide, the rotating shaft 541 cannot drive the first gear 5221 to move in the axial direction A1, and there is no wear problem, which increases the reliability of the first gear pump head 52 and avoids the refrigerant leakage problem.

[0074] The rectangular block cooperates with the rectangular through hole 5227 in a manner that can realize the sliding between the rotating shaft 541 and the first gear 5221 in the axial direction A1, avoiding the problem of abrasion, and can also realize the rotation of the first gear 5221 driven by the rotating shaft 541 in the circumferential direction of the main shaft 5411 of the rotating shaft 541. If the first connecting part 5223 is provided with a circular through hole, and the first end part 5412 and the second end part 5413 are provided with a circular structure that passes through the circular through hole, in the case that the size of the circular through hole is slightly larger than the circular structure, the rotating shaft 541 can slide relative to the first gear 5221, but the first rotating shaft 541 cannot drive the first gear 5221 to rotate. The structure of the second gear pump head 53 is the same as that of the first gear pump head 52, which will not be described here.

[0075] In other embodiments, as shown in Figure 5 and Figure 6 , Figure 5 is a structural schematic diagram of a first gear pump head 52, Figure 6 is a structural schematic diagram of another first gear pump head 52. The first connecting part 5223 can be provided with a triangular through hole 5228, and the first end part 5412 is a triangular structure that cooperates with the triangular through hole 5228, which can realize the sliding between the rotating shaft 541 and the first gear 5221 in the axial direction A1, avoiding the problem of abrasion, and can also realize the rotation of the first gear 5221 driven by the rotating shaft 541 in the circumferential direction of the main shaft 5411 of the rotating shaft 541. Alternatively, the first connecting part 5223 can be a rhombic through hole 5229, and the first end part 5412 is a rhombic structure that cooperates with the rhombic through hole 5229, which can realize the sliding between the rotating shaft 541 and the first gear 5221 in the axial direction A1, avoiding the problem of abrasion, and can also realize the rotation of the first gear 5221 driven by the rotating shaft 541 in the circumferential direction of the main shaft 5411 of the rotating shaft 541.

[0076] Secondly, referring to Figure 7 , Figure 7is a structural schematic view of the refrigerant pump 50. The first gear pump head 52 and the second gear pump head 53 are arranged in parallel, the refrigerant pump 50 is provided with two input ports, i.e. a first input port 511 and a second input port 513, and one output port 512 for transmitting refrigerant. Specifically, the first inlet 5211 is communicated with the first input port 511, the second inlet 5311 is communicated with the second input port 513, and the first outlet 5212 and the second outlet 5312 are both communicated with the output port 512, so as to realize the parallel arrangement of the first gear pump head 52 and the second gear pump head 53. In this way, the refrigerant flowing out of the first outlet 5212 of the first gear pump head 52 will not enter the second gear pump head 53, and the refrigerant flowing out of the second outlet 5312 of the second gear pump head 53 will not enter the first gear pump head 52, that is, the parallel connection of the first gear pump head 52 and the second gear pump head 53 is realized. In other words, the refrigerant input into the refrigerant pump 50 enters the first gear pump head 52 and the second gear pump head 53 from two different input ports respectively and is output from the refrigerant pump 50.

[0077] When the first gear pump head 52 and the second gear pump head 53 are arranged in parallel, the lift of the first gear pump head 52 is the same as the lift of the second gear pump head 53, and both are the same as the required lift of the refrigerant pump 50. When the first gear pump head 52 and the second gear pump head 53 are arranged in parallel, the sum of the flow rate of the first gear pump head 52 and the flow rate of the second gear pump head 53 is equal to the required flow rate of the refrigerant pump 50. That is, the parallel arrangement of the first gear pump head 52 and the second gear pump head 53 can realize flow rate sharing. In the case where the flow rate of the required refrigerant pump 50 is unchanged, when only the first gear pump head 53 is provided, or when the first gear pump head 52 and the second gear pump head 53 are provided and arranged in series, the flow rate of the first gear pump head 52 is the flow rate of the refrigerant pump 50, when the first gear pump head 52 and the second gear pump head 53 are provided and arranged in parallel, the flow rate of the first gear pump head 52 is half of the flow rate of the refrigerant pump 50, and the flow rate of the second gear pump head 53 is also half of the flow rate of the refrigerant pump 50, the flow rate of each gear pump head is reduced by half, and the rotational speed of the shaft 541, the first gear pump head 52 and the second gear pump head 53 is also reduced to half of the original, which can effectively improve the service life of the gear pump head and the reliability of the refrigerant pump 50.

[0078] When the first gear pump head 52 and the second gear pump head 53 are arranged in parallel, the second cavity 517 does not need to be provided, or the volume of the second cavity 517 can be smaller. For other structures when the first gear pump head 52 and the second gear pump head 53 are arranged in parallel, refer to the series arrangement of the first gear pump head 52 and the second gear pump head 53, which will not be described here. For example, the first inlet 5211 is arranged at the bottom region 5213 of the first gear pump head 52, and the second inlet 5311 is arranged at the bottom region 5313 of the second gear pump head 53.

[0079] For referenceFigure 2 and Figure 7 In one specific embodiment, the refrigerant pump 50 is provided with a terminal 510, a power line of the stator 543 is connected to the terminal 510, the stator 543 is powered to generate a rotating magnetic field, the magnetic field generated by the stator 543 interacts with the magnetic field generated by the rotor 542, thereby driving the rotor 542 to rotate, the rotor 542 drives the rotating shaft 541 to rotate, and the rotating shaft 541 can drive the first gear part 522 and the second gear part 532 to rotate, so as to realize the operation of the refrigerant pump 50.

[0080] The first gear pump head 52 and the second gear pump head 53 in the refrigerant pump 50 of the present application are symmetrically arranged on both sides of the rotor 542, which can avoid the wear problem caused by shaft eccentricity; when the first gear pump head 52 and the second gear pump head 53 are arranged in series, the lift can be shared, which can significantly improve the service life of the refrigerant pump 50; when the first gear pump head 52 and the second gear pump head 53 are arranged in parallel, the flow can be shared, which can improve the service life of the refrigerant pump 50; the first gear part 522 of the first gear pump head 52 is in sliding connection with the rotating shaft 541, and the second gear part 532 of the second gear pump head 53 is in sliding connection with the rotating shaft 541, which can avoid the wear problem caused by the running of the rotating shaft 541; when the first gear pump head 52 and the second gear pump head 53 are arranged in series, the second cavity 517 is arranged, which is beneficial to balance the flow of the first gear pump head 52 and the second gear pump head 53.

[0081] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A refrigerant pump, characterized in that, The device includes a first gear pump head, a power unit, and a second gear pump head arranged in sequence. The power unit includes a rotating shaft and a rotor. The middle part of the rotating shaft is fixed to the rotor, and the two ends of the rotating shaft are respectively inserted into the gear parts of the first gear pump head and the gear parts of the second gear pump head. The first gear pump head and the second gear pump head are connected in series. The refrigerant pump includes a housing and a first isolation wall and a second isolation wall located inside the housing. The first isolation wall and the second isolation wall isolate the housing to form a first cavity, a second cavity and a third cavity. The first gear pump head is located in the first cavity, the rotor is located in the second cavity, and the second gear pump head is located in the third cavity. The refrigerant input to the refrigerant pump passes sequentially through the first cavity, the first gear pump head, the second cavity, the second gear pump head and the third cavity and is output from the refrigerant pump. The second gear pump head includes a second inlet, which is located in the bottom region of the second gear pump head; The volume between the second isolation wall and the rotor is greater than the volume between the first isolation wall and the rotor.

2. The refrigerant pump as described in claim 1, characterized in that, In the axial direction of the rotating shaft, the gear portion of the first gear pump head is slidably connected to the rotating shaft.

3. The refrigerant pump as described in claim 2, characterized in that, The gear portion of the first gear pump head is provided with a rectangular through hole, and the end of the rotating shaft is provided with a rectangular block, which passes through the rectangular through hole.

4. The refrigerant pump as described in claim 2, characterized in that, The first gear pump head includes a housing, the gear portion of the first gear pump head is located inside the housing, the housing is fixed to the outer casing of the refrigerant pump, and the rotating shaft is slidably connected to the housing in the axial direction.

5. The refrigerant pump according to any one of claims 1-4, characterized in that, The first gear pump head includes a first inlet located in the bottom region of the first gear pump head.

6. The refrigerant pump as claimed in claim 1, characterized in that, The refrigerant pump includes a baffle located between the rotor and the second isolation wall, and the baffle is close to the rotor.

7. The refrigerant pump according to any one of claims 1-4, characterized in that, The number of the first gear pump heads is at least two, the internal spaces of the at least two first gear pump heads are connected, and the gear parts of the at least two first gear pump heads are spaced apart and are all sleeved on the rotating shaft.

8. A refrigeration system, characterized in that, The device includes an evaporator, a condenser, a compressor, a first one-way valve, a second one-way valve, and a refrigerant pump as described in any one of claims 1-7, wherein the first one-way valve is connected in parallel with the refrigerant pump, and the second one-way valve is connected in parallel with the compressor; the compressor, the condenser, the refrigerant pump, and the evaporator are connected to form a circuit.

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