EP4632290A1

EP4632290A1 - Ejector refrigeration system

Info

Publication number: EP4632290A1
Application number: EP25167854.6A
Authority: EP
Inventors: Jichao Hu; Hongsheng Liu; Xinglei Zhang
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 2024-04-01
Filing date: 2025-04-01
Publication date: 2025-10-15
Also published as: CN120777769A; US20250305738A1

Abstract

An ejector refrigeration system includes: a compressor (1) having a suction port (11) and a discharge port (21); a first heat exchanger (2) connected to the discharge port of the compressor to receive a fluid working medium flowing out from the discharge port of the compressor; and an ejector (3) including a primary flow inlet (31) connected to the first heat exchanger to receive a fluid working medium from the first heat exchanger, a secondary flow inlet (32), an ejector outlet (33) connected to the suction port of the compressor to return a fluid working medium entering the ejector to the suction port of the compressor, and a phase adjustment mechanism configured to adjust a phase state of the fluid working medium entering the primary flow inlet of the ejector or adjust a gas-liquid ratio of the fluid working medium at the primary flow inlet.

Description

Technical Field

This application relates to the field of refrigeration devices, and particularly, to an ejector refrigeration system.

Background Art

As illustrated in FIG. 1, an ejector refrigeration system using carbon dioxide as a fluid working medium and using an ejector is disclosed, and the ejector refrigeration system can save electrical energy when operating in a transcritical state.
In the ejector refrigeration system, the fluid working medium from a compressor 100 enters an ejector 300 through a first heat exchanger 200, the fluid working medium entering through a second heat exchanger 500 (evaporator) is mixed in the ejector 300 and then enters a gas-liquid separator 400. After the gas-liquid separation, a gaseous working medium returns to the compressor 100, the liquid working medium enters the second heat exchanger 500 (evaporator) again, the second heat exchanger 500 exchanges heat with, for example, external air, so that a temperature of the external air is decreased to achieve a refrigeration effect.
However, when an external ambient temperature is relatively low, since a fluid pressure at an outlet of the first heat exchanger 200 is excessively low, the ejector 300 cannot provide sufficient pressure lift, and a working medium pressure at an outlet of the ejector 300 cannot be raised to a specified pressure, which greatly reduces an effect of the ejector 300 in the ejector refrigeration system and may even cause the ejector refrigeration system to malfunction and fail to operate normally.
In the prior art, to ensure the pressure lift of the working medium at an ejector outlet, the following solutions are provided:

1. A booster pump 600 is disposed between the gas-liquid separator 400 and the second heat exchanger 500 to compensate for the insufficient pressure lift of the ejector and ensure normal operation of the refrigeration system.
2. A first bypass branch 700 and a second bypass branch 710 that bypass the ejector 300 are added to ensure the normal operation of the refrigeration system.

To bypass the ejector, a first solenoid valve 720 is provided on the first bypass branch 700, a second solenoid valve 730 is provided on the second bypass branch 710, a third solenoid valve 740 is provided at a primary flow inlet 310, a fourth solenoid valve 750 is disposed at a secondary flow inlet 320, and a pressure regulating valve 800 is disposed between the gas-liquid separator 400 and a return gas inlet of the compressor 100.
Although the above solutions can ensure the normal operation of the refrigeration system to a certain extent, there are problems of reduced refrigeration energy efficiency, complex structure and high cost.

Summary of the Invention

This application provides an ejector refrigeration system to resolve or alleviate some of the problems in the prior art.
A first aspect of this application provides an ejector refrigeration system including: a compressor having a suction port and a discharge port; a first heat exchanger connected to the discharge port of the compressor to receive a fluid working medium flowing out from the discharge port of the compressor; and an ejector including a primary flow inlet connected to the first heat exchanger to receive a fluid working medium from the first heat exchanger, a secondary flow inlet, and an ejector outlet connected to the suction port of the compressor to return a fluid working medium entering the ejector to the suction port of the compressor. The ejector refrigeration system further includes a phase adjustment mechanism configured to adjust a phase state of the fluid working medium entering the primary flow inlet of the ejector.
Optionally, the phase adjustment mechanism is configured to adjust the fluid working medium entering the primary flow inlet of the ejector into a gas-liquid two-phase state in response to an external ambient temperature being lower than a specified value.
Optionally, the ejector refrigeration system further includes: a second heat exchanger; and a gas-liquid separator including an inlet connected to the ejector outlet, a gas outlet connected to the suction port of the compressor, and a liquid outlet connected to the secondary flow inlet via the second heat exchanger.
Optionally, the ejector refrigeration system further includes a differential pressure sensor configured to measure a differential pressure between the secondary flow inlet of the ejector and the ejector outlet, the phase adjustment mechanism being in communication connection with the differential pressure sensor, or the ejector refrigeration system further includes a pressure detection assembly configured to detect pressures of the ejector outlet and the secondary flow inlet, the phase adjustment mechanism being in communication connection with the pressure detection assembly.
Optionally, the ejector refrigeration system further includes: a dryness sensor disposed at the primary flow inlet, the phase adjustment mechanism being in communication connection with the dryness sensor.
Optionally, the ejector refrigeration system further includes an expansion valve disposed between the primary flow inlet and the first heat exchanger, in which the phase adjustment mechanism is a mechanism for controlling an opening degree of the expansion valve.
Optionally, the phase adjustment mechanism is a mechanism for controlling a rotation speed of a fan of the first heat exchanger.
Optionally, the ejector refrigeration system further includes: a bypass pipeline connected, at one end, between the discharge port of the compressor and the first heat exchanger, and connected, at the other end, between an outlet of the first heat exchanger and the primary flow inlet; and a first opening regulating valve disposed in the bypass pipeline, in which the phase adjustment mechanism is a mechanism for adjusting an opening degree of the first opening regulating valve.
Optionally, the ejector refrigeration system further includes a reservoir including: a reservoir inlet communicating with a first pipe section of the first heat exchanger to receive a fluid working medium at an outlet of the first pipe section; a reservoir liquid refrigerant outlet communicating with a second pipe section of the first heat exchanger; and a reservoir gaseous refrigerant outlet located at the top of the reservoir and connected between an outlet of the first heat exchanger and the primary flow inlet of the ejector.
Optionally, the ejector refrigeration system further includes a second opening regulating valve disposed between the reservoir gaseous refrigerant outlet and the primary flow inlet, in which the phase adjustment mechanism is a mechanism for adjusting an opening degree of the second opening regulating valve.

Descriptions of the Drawings

Certain exemplary embodiments will now be described in greater detail by way of example only and with reference to the accompanying drawings in which:

FIG. 1 is a schematic structural diagram of an ejector refrigeration system in the prior art;
FIG. 2 is a schematic structural diagram of an ejector refrigeration system;
FIG. 3 is a schematic structural diagram of an ejector refrigeration system; and
FIG. 4 is a schematic structural diagram of an ejector refrigeration system.

List of Reference Numerals:

Prior Art:

Compressor 100, first heat exchanger 200, ejector 300, primary flow inlet 310, secondary flow inlet 320, gas-liquid separator 400, second heat exchanger 500, booster pump 600, first bypass branch 700, second bypass branch 710, first solenoid valve 720, second solenoid valve 730, third solenoid valve 740, fourth solenoid valve 750, and pressure regulating valve 800.

Present Application:

Compressor 1, suction port 11, discharge port 12, first heat exchanger 2, fan 21, ejector 3, primary flow inlet 31, secondary flow inlet 32, ejector outlet 33, second heat exchanger 4, gas-liquid separator 5, inlet 51, gas outlet 52, liquid outlet 53, throttle valve 61, expansion valve 62, first opening regulating valve 63, second opening regulating valve 64, differential pressure sensor 7, bypass pipeline 8, reservoir 9, reservoir inlet 91, reservoir liquid refrigerant outlet 92, and reservoir gaseous refrigerant outlet 93.

Detailed Description

Embodiments of this application are described below, by way of example only and without limitation, with reference to the accompanying drawings, and obviously, the described embodiments are merely some of the possible embodiments, and are not all embodiments falling within the scope of the invention as defined by the appended claims.

As illustrated in FIG. 2, a first aspect of this application provides an ejector refrigeration system including a compressor 1, a first heat exchanger 2, an ejector 3, a phase adjustment mechanism (not illustrated), a second heat exchanger 4, a gas-liquid separator 5 and a throttle valve 61. The compressor 1 has a suction port 11 and a discharge port 12. The first heat exchanger 2 is connected to the discharge port 12 of the compressor 1 to receive a fluid working medium flowing out from the discharge port 12 of the compressor 1. The ejector 3 includes a primary flow inlet 31, a secondary flow inlet 32 and an ejector outlet 33, the primary flow inlet 31 is connected to the first heat exchanger 2 to receive a fluid working medium from the first heat exchanger 2, and the ejector outlet 33 is connected to the suction port 11 of the compressor 1 to return a fluid working medium entering the ejector 3 to the suction port 11 of the compressor 1. The phase adjustment mechanism adjusts a phase state of the fluid working medium entering the primary flow inlet 31 of the ejector 3, and specifically adjusts the fluid working medium entering the primary flow inlet 31 of the ejector 3 to a gas-liquid two-phase state or adjusts the content of a gaseous working medium in the gas-liquid two-phase state.
The gas-liquid separator 5 is disposed between the ejector 3 and the compressor 1. The gas-liquid separator 5 includes an inlet 51, a gas outlet 52 and a liquid outlet 53. The inlet 51 of the gas-liquid separator 5 is connected to the ejector outlet 33, and the gas outlet 52 is connected to the suction port 11 of the compressor 1. The liquid outlet 53 is connected to the secondary flow inlet 32 via the second heat exchanger 4, and the throttle valve 61 is disposed between the liquid outlet 53 and the second heat exchanger 4.
The ejector refrigeration system of this application includes a first loop and a second loop. In the first loop, the gaseous working medium discharged from the compressor 1 sequentially passes through the first heat exchanger 2, the ejector 3, and the gas-liquid separator 5 and then returns to the compressor 1. In the second loop, a liquid working medium discharged from the liquid outlet 53 of the gas-liquid separator 5 sequentially passes through the throttle valve 61, the second heat exchanger 4, and the secondary flow inlet 32 of the ejector 3 and then returns to the inlet 51 of the gas-liquid separator 5.
It should be noted that the ejector refrigeration system in this application may perform heating operation in addition to cooling operation.
The term "connected" in this application may refer to a direct connection or an indirect connection
The fluid working medium in this application is carbon dioxide, which has inexpensive, non-flammable, non-toxic and good environmental characteristics.
The fluid working medium at the outlet of the compressor 1 is gaseous carbon dioxide in a subcritical state (carbon dioxide is at a temperature lower than 31.1°C and a pressure lower than 7.38 MPa).
The ejector 3 includes a nozzle, a mixing chamber, a diffuser and a suction chamber. The nozzle is configured to convert pressure energy of the fluid working medium into kinetic energy and suction the gaseous working medium entering from the suction chamber, the mixing chamber is configured to mix the gaseous working medium suctioned by the suction chamber with the fluid working medium ejected from the nozzle, and the diffuser is configured to convert the kinetic energy of the mixed fluid working medium into pressure energy for discharge.
The structure of the ejector 3 is a common application form in the art, and details are not described herein again.
In the embodiment of this application, the first heat exchanger 2 is a gas cooler, the second heat exchanger 4 is an evaporator, and the gas-liquid separator 5 is configured to separate the gaseous working medium from the liquid working medium, and may be a flash tank or another mechanism that can separate the gaseous working medium from the liquid working medium. This application does not limit the specific structural form of the gas-liquid separator 5, and those skilled in the art can select a suitable gas-liquid separator 5 as needed.
A phase adjustment mechanism adjusts the fluid working medium entering the primary flow inlet 31 of the ejector 3 to a gas-liquid two-phase state or adjusts the content of the gaseous working medium in the gas-liquid two-phase state.
Specifically, under a first working condition, the fluid working medium entering the first heat exchanger 2 is completely cooled to a liquid state, and the fluid working medium entering the primary flow inlet 31 is in a purely liquid state. Under the first working condition, the phase adjustment mechanism adjusts a phase state of the fluid working medium entering the primary flow inlet 31 of the ejector 3, which specifically refers to adjusting the fluid working medium of the primary flow inlet 31 to a gas-liquid two-phase state.
Under a second working condition, the fluid working medium discharged by the first heat exchanger 2 is a mixed working medium of the liquid working medium and a small amount of gaseous working medium. Under the second working condition, the phase adjustment mechanism adjusts the phase state of the fluid working medium entering the primary flow inlet 31 of the ejector 3, which specifically refers to adjusting the content of the gaseous working medium in the fluid working medium at the primary flow inlet 31, such as increasing the content of the gaseous working medium in the fluid working medium.
In some cases, adjusting the phase state of the fluid working medium entering the primary flow inlet 31 of the ejector 3 may also be understood as adjusting the content of the gaseous working medium in the fluid working medium entering the primary flow inlet 31.
In this application, the phase adjustment mechanism adjusts the fluid working medium entering the primary flow inlet 31 of the ejector 3 to the gas-liquid two-phase state or increases the content of the gaseous working medium in the gas-liquid two-phase state, thereby ensuring that the ejector 3 can generate sufficient pressure lift and enabling the uninterrupted operation of the ejector refrigeration system.
In addition, since the gaseous working medium discharged from the first heat exchanger 2 is a fluid working medium circulating inside the ejector refrigeration system, there is no need to introduce an additional fluid working medium, which reduces energy consumption and is conducive to cost savings.
In this application, the ejector refrigeration system further includes an ambient temperature sensor (not illustrated) configured to detect an external ambient temperature.
The phase adjustment mechanism is configured to adjust the fluid working medium entering the primary flow inlet 31 of the ejector 3 to a gas-liquid two-phase state in response to the external ambient temperature being lower than a specified value (for example, the external ambient temperature is lower than 15°C).
In this application, when the external ambient temperature is lower than the specified value, the pressure of the fluid working medium at the outlet of the first heat exchanger 2 decreases relatively, resulting in the ejector 3 being unable to provide sufficient pressure lift to ensure the normal operation of the second loop.
By adjusting the fluid working medium entering the primary flow inlet 31 of the ejector 3 to the gas-liquid two-phase state, the pressure lift of the ejector 3 can be increased.
Compared with a case where the fluid working medium entering the primary flow inlet 31 of the ejector 3 is entirely in the liquid state and the pressure at the primary flow inlet 31 is relatively low when the external ambient temperature is lower than the specified value, this application includes the fluid working medium that is partly the gaseous working medium, which is beneficial for ensuring the pressure lift of the ejector 3 and the uninterrupted operation of the ejector refrigeration system.
Further, the ejector refrigeration system further includes a differential pressure sensor 7 configured to measure a differential pressure between the secondary flow inlet 32 of the ejector 3 and the ejector outlet 33, and the phase adjustment mechanism is in communication connection with the differential pressure sensor 7.
In this application, the phase adjustment mechanism may adjust, based on a differential pressure detection result of the differential pressure sensor 7, the fluid working medium entering the primary flow inlet 31 to a gas-liquid two-phase state or adjust the content of the gaseous working medium in the gas-liquid two-phase state.
Specifically, according to different differential pressure detection results, the fluid working medium entering the primary flow inlet 31 is adjusted to the gas-liquid two-phase state or the content of the gaseous working medium in the gas-liquid two-phase state is adjusted to ensure the pressure lift of the ejector 3, thereby avoiding a situation where the ejector 3 cannot work normally due to the excessive or small amount of the gaseous working medium, and improving operation reliability of the ejector refrigeration system.
A differential pressure between a working medium pressure at the ejector outlet 33 and a working medium pressure at the secondary flow inlet 32 is large, which indicates that the pressure lift of the ejector 3 is large, and thus the content of the gaseous working medium at the primary flow inlet 31 can be reduced.
The differential pressure between the working medium pressure at the ejector outlet 33 and the working medium pressure at the secondary flow inlet 32 is small, which indicates that the pressure lift of the ejector 3 is small, and thus the pressure lift of the ejector 3 needs to be increased by increasing the content of the gaseous working medium in the fluid working medium at the primary flow inlet 31.
In some embodiments, pressure sensors may also be respectively disposed at the secondary flow inlet 32 and the ejector outlet 33 to form a pressure detection assembly, so as to detect the pressure at the secondary flow inlet 32 and the pressure at the ejector outlet 33, and the phase adjustment mechanism adjusts the fluid working medium of the primary flow inlet 31 to the gas-liquid two-phase state or adjusts the content of the gaseous working medium in the gas-liquid two-phase state according to the differential pressure between the secondary flow inlet 32 and the ejector outlet 33.
This application does not limit a method for acquiring the differential pressure, and those skilled in the art may select a suitable differential pressure detection structure as needed.
The pressure sensor is a common application form in the art, and details are not described herein again.
In some other embodiments, a dryness sensor (not illustrated) may be disposed at the primary flow inlet 31 to detect the content of the gaseous working medium in the fluid working medium at the primary flow inlet 31.
The phase adjustment mechanism is in communication connection with the dryness sensor, and the phase adjustment mechanism adjusts the gas-liquid two-phase state of the fluid working medium entering the primary flow inlet 31 according to a detection result (content of the gaseous working medium in the fluid working medium entering the primary flow inlet 31) of the dryness sensor, and controls the content of the gaseous working medium in the fluid working medium, thereby ensuring the pressure lift of the ejector 3, avoiding the situation where the ejector 3 cannot work normally due to the excessive or small amount of the gaseous working medium, and improving the operation reliability of the ejector refrigeration system.
In an optional technical solution, the phase adjustment mechanism is a mechanism for controlling a rotation speed of a fan 21 of the first heat exchanger 2.
Specifically, the phase adjustment mechanism may be a controller of the ejector refrigeration system.
The controller may be an integrated circuit chip with a signal processing capability.
The controller may be a general-purpose processor, including a central processing unit (CPU), or may be a chip such as a single-chip microcomputer, a microcontroller unit (MCU), a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), or an embedded ARM. The controller may implement or perform control steps disclosed in the embodiments of this application.
When the phase adjustment mechanism performs control to reduce the rotation speed of the fan 21 of the first heat exchanger 2, the fluid working medium cannot be completely liquefied in the first heat exchanger 2, that is, a part of gaseous working medium in the fluid working medium at the outlet of the first heat exchanger 2 is not condensed into a liquid working medium, and the fluid working medium at the outlet of the first heat exchanger 2 is in a gas-liquid two-phase state.
By reducing the rotation speed of the fan 21, this application can adjust the fluid working medium entering the primary flow inlet 31 to the gas-liquid two-phase state or adjust the content of the gaseous working medium in the gas-liquid two-phase state without adding additional components, which is beneficial for saving costs compared with the solution in the prior art in which a booster pump 600 or first and second bypass branches 700 and 710 are added.
Further, the phase adjustment mechanism may adjust the rotation speed of the fan 21 according to the differential pressure detection result of the differential pressure sensor 7 or the detection result of the dryness sensor, and thus a ratio of gaseous working medium to liquid working medium at the primary flow inlet 31 is within a reasonable range, thereby ensuring the normal operation of the ejector 3 and improving the operation reliability of the ejector refrigeration system.

As illustrated in FIG. 3, a second embodiment of this application provides an ejector refrigeration system, which differs from the first embodiment in that the ejector refrigeration system further includes an expansion valve 62 disposed between the primary flow inlet 31 and the first heat exchanger 2, and the phase adjustment mechanism is a mechanism for controlling an opening degree of the expansion valve 62.
Specifically, the phase adjustment mechanism controls the opening degree of the expansion valve 62 such that the liquid working medium at the outlet of the first heat exchanger 2 becomes a gas-liquid two-phase medium through the expansion valve 62, and thus the fluid working medium entering the primary flow inlet 31 includes the gas-liquid two-phase state or the content of the gaseous working medium entering the primary flow inlet 31 is adjusted.
In this application, the fluid working medium entering the primary flow inlet 31 can be adjusted to the gas-liquid two-phase state or the content of the gaseous working medium in the gas-liquid two-phase state can be adjusted only by adding the expansion valve 62 and controlling the opening degree of the expansion valve 62, which is simple in structure, does not require complex pipeline connection, and is conducive to saving costs.
Further, in this embodiment, the differential pressure sensor 7 or the dryness sensor is further included, which is respectively configured to detect the differential pressure between the secondary flow inlet 32 of the ejector 3 and the ejector outlet 33 or the content of the gaseous working medium in the fluid working medium at the primary flow inlet 31, and the phase adjustment mechanism is in communication connection with the differential pressure sensor 7 or the dryness sensor.
The phase adjustment mechanism can adjust the opening degree of the expansion valve 62 according to the differential pressure detection result of the differential pressure sensor 7 or the detection result of the dryness sensor, so that the fluid working medium entering the primary flow inlet 31 is adjusted to the gas-liquid two-phase state or the content of the gaseous working medium is adjusted, thereby avoiding the situation where the ejector 3 cannot work normally and improving the operation reliability of the ejector refrigeration system.

As illustrated in FIG. 4, a third embodiment of this application provides an ejector refrigeration system, which differs from the first embodiment in that the ejector refrigeration system further includes a bypass pipeline 8 and a first opening regulating valve 63. One end of the bypass pipeline 8 is connected between the discharge port 12 of the compressor 1 and the first heat exchanger 2, and the other end of the bypass pipeline 8 is connected between the outlet of the first heat exchanger 2 and the primary flow inlet 31. The first opening regulating valve 63 is provided in the bypass pipeline 8, and the phase adjustment mechanism is a mechanism for adjusting an opening degree of the first opening regulating valve 63.
In this application, the fluid working medium at the outlet of the compressor 1 is a gaseous working medium, and the gaseous working medium enters the primary flow inlet 31 after being mixed with the working medium at the outlet of the first heat exchanger 2 through the bypass pipeline 8, and thus the fluid working medium at the primary flow inlet 31 is adjusted to a gas-liquid two-phase state or the content of the gaseous working medium in the gas-liquid two-phase state is adjusted.
By adjusting the opening degree of the first opening regulating valve 63, the content of the gaseous working medium entering the primary flow inlet 31 can be changed as needed, and the fluid working medium at the primary flow inlet 31 is further adjusted to a required gas-liquid ratio, thereby ensuring the pressure lift of the ejector 3 and the reliable operation of the ejector refrigeration system.
In this application, only the bypass pipeline 8 with the first opening regulating valve 63 needs to be added to change the gas-liquid ratio at the primary flow inlet 31, thereby ensuring that the ejector 3 provides sufficient pressure lift and uninterrupted operation of the ejector refrigeration system in a low temperature environment, and improving operation reliability of the ejector refrigeration system.
Compared with a solution in the prior art in which the first and second bypass branches 700 and 710 need to bypass the ejector 300, the structure of the ejector refrigeration system is simplified, and costs are reduced.
Further, the phase adjustment mechanism may adjust the opening degree of the first opening regulating valve 63 according to the differential pressure detection result of the differential pressure sensor 7 or the detection result of the dryness sensor or the pressure sensor, and thus the gas-liquid ratio at the primary flow inlet 31 is adjusted to a reasonable range, thereby ensuring the normal operation of the ejector 3 and improving the operation reliability of the ejector refrigeration system.

As illustrated in FIG. 4, a fourth embodiment of this application provides an ejector refrigeration system, which differs from the third embodiment in that the ejector refrigeration system further includes a reservoir 9. The reservoir 9 includes a reservoir inlet 91, a reservoir liquid refrigerant outlet 92 and a reservoir gaseous refrigerant outlet 93. The reservoir inlet 91 is in communication with a first pipe section of the first heat exchanger 2 to receive a fluid working medium at an outlet of the first pipe section, the reservoir liquid refrigerant outlet 92 is in communication with a second pipe section of the first heat exchanger 2, the reservoir gaseous refrigerant outlet 93 is located at the top of the reservoir 9, and the reservoir gaseous refrigerant outlet 93 is connected between the outlet of the first heat exchanger 2 and the primary flow inlet 31.
In this application, by disposing the reservoir 9, the fluid working medium in the first heat exchanger 2 enters the reservoir 9 when the fluid working medium is not sufficiently condensed into a liquid state (including the gas-liquid two-phase state). Further, due to different densities of the gaseous working medium and the liquid working medium, the gaseous working medium enters the top of the reservoir 9 upward and is discharged from the top of the reservoir 9, and is mixed with the working medium at the outlet of the first heat exchanger 2, and then enters the primary flow inlet 31 to achieve the adjustment of the gas-liquid ratio of the working medium at the primary flow inlet 31. The liquid working medium is deposited at the bottom of the reservoir 9 and enters the second pipe section of the first heat exchanger 2.
It should be noted that the first pipe section and the second pipe section in this application represent pipe sections at different positions in a coil of the first heat exchanger 2.
Those skilled in the art may choose to connect the reservoir inlet 91 and the reservoir liquid refrigerant outlet 92 to different positions of the coil of the first heat exchanger 2 according to actual conditions, and specific communication positions of the reservoir inlet 91 and the reservoir liquid refrigerant outlet 92 with the coil of the first heat exchanger 2 are not limited in this application.
Further, the ejector refrigeration system further includes a second opening regulating valve 64 disposed between the reservoir gaseous refrigerant outlet 93 and the primary flow inlet 31. The phase adjustment mechanism is a mechanism for adjusting an opening degree of the second opening regulating valve 64.
Specifically, the phase adjustment mechanism can adjust the amount of gaseous refrigerant discharged from the reservoir gaseous refrigerant outlet 93 by adjusting the opening degree of the second opening regulating valve 64, and the gaseous refrigerant is mixed with liquid refrigerant at the outlet of the first heat exchanger 2 and then enters the primary flow inlet 31, that is, the content of the gaseous refrigerant in the fluid working medium entering the primary flow inlet 31 is adjusted.
By increasing the opening degree of the second opening regulating valve 64, the content of the gaseous refrigerant entering the primary flow inlet 31 can be increased, and the boosting capability of the ejector 3 is improved.
Further, the phase adjustment mechanism may adjust the opening degree of the first opening regulating valve 63 and/or the second opening regulating valve 64 according to the differential pressure detection result of the differential pressure sensor 7 or the detection result of the dryness sensor or the pressure sensor, and thus the gas-liquid ratio at the primary flow inlet 31 is adjusted to a reasonable range, thereby ensuring the normal operation of the ejector and improving the operation reliability of the ejector refrigeration system.
It should be noted that although the above embodiments are illustrated in this application, those skilled in the art may understand that the above embodiments may be combined with each other to form ejector refrigeration systems with different structures, and details are not described herein again.
In addition, those skilled in the art may also change a source of the gaseous working medium entering the primary flow inlet 31 according to actual conditions, which is not limited to conversion from the working medium circulating inside the ejector refrigeration system.

The structure of the ejector refrigeration system of this application has been specifically described above, and numerical simulation is performed on the ejector refrigeration system by fluid dynamics (CFD) software below to acquire pressure lift (differential pressure between the ejector outlet 33 and the secondary flow inlet 32) data of different ejector refrigeration systems.

Primary flow inlet pressure	Pressure increase (kPa) of existing ejector system	Pressure increase (kPa) of ejector system (dryness = 0.2) in this application
6500 kPa	176	308
5000 kPa	108	251

In the table, when the pressure at the primary flow inlet 31 is 6500 kPa, the pressure of the existing ejector system increases by 176 kPa, whereas the pressure of the ejector system in this application increases by 308 kPa in the case where the ejector refrigeration system in any one of the embodiments 1 to 4 of this application is used and the dryness is controlled to be 0.2, that is, the mass of the gaseous working medium at the primary flow inlet 31 accounts for 20% of the total weight of the fluid working medium at the primary flow inlet 31.
When the pressure at the primary flow inlet 31 is 5000 kPa, the pressure of the existing ejector system increases by 108 kPa, whereas the pressure of the ejector system in this application increases by 251 kPa in the case where the ejector refrigeration system in any one of the embodiments 1 to 4 of this application is used and the dryness is controlled to be 0.2.
In this application, by adjusting the content of the gaseous working medium in the fluid working medium entering the primary flow inlet 31 to 20%, the pressure increase of the ejector is increased by about 130 kPa compared with the prior art, thereby greatly increasing the pressure at the inlet of the compressor, and further increasing the energy efficiency ratio of the refrigeration system.
The above embodiments are merely preferred embodiments of this application and are not intended to limit this application. The skilled person will understand that various modifications may be made to the described embodiments while remaining within the scope of the appended claims. For the avoidance of doubt, the scope of protection is limited only by the claims.

Claims

An ejector refrigeration system comprising:
a compressor (1) having a suction port (11) and a discharge port (21);

a first heat exchanger (2) connected to the discharge port of the compressor to receive a fluid working medium flowing out from the discharge port of the compressor; and

an ejector (3) including a primary flow inlet (31) connected to the first heat exchanger to receive a fluid working medium from the first heat exchanger, a secondary flow inlet (32), and an ejector outlet (33) connected to the suction port of the compressor to return a fluid working medium entering the ejector to the suction port of the compressor, wherein

the ejector refrigeration system further comprises:
a phase adjustment mechanism configured to adjust a phase state of the fluid working medium entering the primary flow inlet of the ejector.
The ejector refrigeration system according to claim 1, wherein the phase adjustment mechanism is configured to adjust the fluid working medium entering the primary flow inlet of the ejector into a gas-liquid two-phase state in response to an external ambient temperature being lower than a specified value.
The ejector refrigeration system according to claim 1, further comprising:
a second heat exchanger (4); and

a gas-liquid separator (5) including an inlet (51) connected to the ejector outlet, a gas outlet (52) connected to the suction port of the compressor, and a liquid outlet (53) connected to the secondary flow inlet via the second heat exchanger.
The ejector refrigeration system according to claim 1, further comprising:
a differential pressure sensor (7) configured to measure a differential pressure between the secondary flow inlet of the ejector and the ejector outlet, the phase adjustment mechanism being in communication connection with the differential pressure sensor, or

the ejector refrigeration system further comprising:
a pressure detection assembly configured to detect pressures of the ejector outlet and the secondary flow inlet, the phase adjustment mechanism being in communication connection with the pressure detection assembly.
The ejector refrigeration system according to claim 1, further comprising:
a dryness sensor disposed at the primary flow inlet, the phase adjustment mechanism being in communication connection with the dryness sensor.
The ejector refrigeration system according to any one of claims 1 to 5, further comprising:
an expansion valve disposed between the primary flow inlet and the first heat exchanger, wherein

the phase adjustment mechanism is a mechanism for controlling an opening degree of the expansion valve.
The ejector refrigeration system according to any one of claims 1 to 5, wherein
the phase adjustment mechanism is a mechanism for controlling a rotation speed of a fan of the first heat exchanger.
The ejector refrigeration system according to any one of claims 1 to 5, further comprising:
a bypass pipeline (8) connected, at one end, between the discharge port of the compressor and the first heat exchanger, and connected, at the other end, between an outlet of the first heat exchanger and the primary flow inlet; and

a first opening regulating valve (63) disposed in the bypass pipeline, wherein

the phase adjustment mechanism is a mechanism for adjusting an opening degree of the first opening regulating valve.
The ejector refrigeration system according to any one of claims 1 to 5, further comprising:
a reservoir (9) including:
a reservoir inlet (91) communicating with a first pipe section of the first heat exchanger to receive a fluid working medium at an outlet of the first pipe section;

a reservoir liquid refrigerant outlet (92) communicating with a second pipe section of the first heat exchanger; and

a reservoir gaseous refrigerant outlet (93) located at the top of the reservoir and connected between an outlet of the first heat exchanger and the primary flow inlet.
The ejector refrigeration system according to claim 9, further comprising:
a second opening regulating valve (64) disposed between the reservoir gaseous refrigerant outlet and the primary flow inlet, wherein

the phase adjustment mechanism is a mechanism for adjusting an opening degree of the second opening regulating valve.