阅读说明：本技术 用于制冷系统的过滤结构及制冷系统 (A filtration and refrigerating system for refrigerating system ) 是由 俞国新 朱万朋 殷纪强 韩聪 刘增岳 李思茹 刘洋 于 2020-06-11 设计创作，主要内容包括：本发明提供了一种用于制冷系统的过滤结构及制冷系统,过滤结构包括过滤器和流体驱动装置。过滤器用于设置在制冷系统的冷媒流路中对沿第一方向流过其内滤芯的冷媒进行过滤,流体驱动装置邻接于过滤器,配置成受控地促使冷媒沿与第一方向相反的第二方向以预设流速阈值之上的流速流过过滤器,对过滤器内的过滤器的滤芯进行冲刷。本发明的过滤结构能够实现对制冷系统的过滤器进行冲刷清洗、收集杂质以及排出杂质等功能,有效地提高了冷媒的洁净度,从而优化了制冷系统的换热效率。(The invention provides a filtering structure for a refrigerating system and the refrigerating system. The fluid driving device is adjacent to the filter and is configured to controllably promote the refrigerant to flow through the filter in a second direction opposite to the first direction at a flow rate above a preset flow rate threshold value so as to flush the filter element of the filter in the filter. The filtering structure can realize the functions of flushing and cleaning the filter of the refrigerating system, collecting impurities, discharging the impurities and the like, and effectively improves the cleanliness of a refrigerant, thereby optimizing the heat exchange efficiency of the refrigerating system.)

1. A filter structure for a refrigeration system, comprising:

the filter is arranged in a refrigerant flow path of the refrigerating system and used for filtering the refrigerant flowing through a filter element in the refrigerant flow path along a first direction; and

a fluid drive device adjacent to the filter and configured to controllably cause coolant to flow through the filter in a second direction opposite the first direction at a flow rate above a predetermined flow rate threshold to flush a filter element of the filter within the filter.

2. The filtration structure of claim 1,

a first pipe fitting is formed at the refrigerant outlet of the filter, and a second pipe fitting is formed at the refrigerant inlet of the filter; and is

The filter structure further includes:

a backwash pipe having a first end communicating with the first pipe and a second end communicating with the second pipe, the backwash pipe being configured such that a refrigerant for flushing the filter in the second direction circulates between the backwash pipe and the filter; and

and the flow path switching device is configured to controllably switch a refrigerant flow path so that the refrigerant flows into the filter through the second pipe fitting and flows out of the first pipe fitting along the first direction, or the refrigerant circularly flows between the backwashing pipe and the filter along the second direction.

3. The filter structure according to claim 2, the fluid driving device further comprising:

the two ends of the bypass pipe are respectively communicated with the first pipe fitting;

an ejector disposed on the bypass pipe and configured to urge the refrigerant entering from the inlet end of the ejector to flow out in the second direction; and

and the outlet valve is arranged at the outlet end of the ejector and is configured to controllably close the outlet end of the ejector when the refrigerant flows along the first direction so as to prevent the refrigerant from flowing into the outlet end of the ejector.

4. The filter structure according to claim 3, the flow path switching device comprising:

the first valve is arranged at the end part of the first pipe fitting;

a second valve provided at an end of the second pipe;

a third valve disposed in the backwash tube adjacent the first end thereof;

a fourth valve disposed in the backwash pipe adjacent the second end thereof;

a fifth valve disposed on the first tube between the outlet end of the bypass tube and the first end of the backwash tube; and is

Is configured to:

when the pressure difference between the front and the back of a filter element of the filter is smaller than or equal to a preset pressure difference threshold value, the first valve, the second valve and the fifth valve are controlled to be opened, and the third valve and the fourth valve are controlled to be closed, so that the refrigerant flows into the filter through the second pipe fitting and flows out of the first pipe fitting along the first direction; or

When the pressure difference between the front and the rear of a filter element of the filter is larger than a preset pressure difference threshold value, the first valve, the second valve and the fifth valve are controlled to be closed, and the third valve and the fourth valve are controlled to be opened, so that the refrigerant circularly flows among the backwashing pipe, the bypass pipe and the filter along the second direction.

5. The filter structure according to claim 4,

the backwash pipe is provided with a pipe wall protruding outwards along the radial direction of the backwash pipe to form a sewage storage tank, and impurities carried by the refrigerant are deposited in the sewage storage tank when the refrigerant flows through the backwash pipe.

6. The filter structure according to claim 5,

the sewage storage tank is positioned between the third valve and the fourth valve; and is

And the bottom of the sewage storage tank is connected with a sewage discharge pipe, the sewage discharge pipe is provided with a sewage discharge valve for controlling the opening and closing of the sewage discharge pipe, and the sewage discharge valve is controlled to be opened after the third valve and the fourth valve are closed so as to discharge impurities precipitated in the sewage storage tank.

7. The filter structure according to claim 5,

the dirt storage tank is positioned below the backwashing pipe so as to ensure that the refrigerant enters the dirt storage tank when flowing through the backwashing pipe.

8. The filter structure according to claim 1, further comprising:

a differential pressure sensor disposed on the filter and configured to detect a differential pressure across a filter element of the filter.

9. The filtration structure of claim 1,

the filter element comprises a first fixing frame, a supporting spring, a second fixing frame, a drying agent layer, a filter screen and a third fixing frame which are sequentially arranged along the first direction, and two ends of the supporting spring are respectively connected with the first fixing frame and the second fixing frame.

10. A refrigeration system comprising the filter structure of any of claims 1-9.

Technical Field

The present disclosure relates to refrigeration systems, and particularly to a filtering structure for a refrigeration system and a refrigeration system.

Background

Substances and impurities harmful to equipment in the processes of maintenance, assembly, refrigerant filling and the like of the refrigeration system often enter a flow path of the refrigeration system, such as water vapor in air, welding slag and the like, the substances affect the safety and the service life of the refrigeration system, for example, the refrigerant can be hydrolyzed after meeting water to generate acidic substances, corrosion is generated on the wall of a metal pipe, large-particle impurities can cause pipeline blockage and the like. In order to overcome the defects, a filter for filtering impurities is arranged in a refrigeration system in the related art, but after the refrigeration system runs for a long time, a filter screen is easy to block, and the heat exchange efficiency is influenced.

Disclosure of Invention

It is an object of the present invention to provide a filter structure that enables cleaning of the filter.

A further object of the present invention is to collect impurities from the filter element of the filter and to maintain the stability of the refrigeration system during normal operation when the impurities are discharged.

In particular, the present invention provides a filtering structure for a refrigeration system, comprising:

the filter is arranged in a refrigerant flow path of the refrigerating system and used for filtering the refrigerant flowing through a filter element in the refrigerant flow path along a first direction; and

a fluid drive device adjacent to the filter and configured to controllably cause coolant to flow through the filter in a second direction opposite the first direction at a flow rate above a predetermined flow rate threshold to flush a filter element of the filter within the filter.

Furthermore, a first pipe fitting is formed at a refrigerant outlet of the filter, and a second pipe fitting is formed at a refrigerant inlet of the filter; and the filter structure further comprises:

a backwash pipe having a first end communicating with the first pipe and a second end communicating with the second pipe, the backwash pipe being configured such that a refrigerant for flushing the filter in the second direction circulates between the backwash pipe and the filter; and

and the flow path switching device is configured to controllably switch a refrigerant flow path so that the refrigerant flows into the filter through the second pipe fitting and flows out of the first pipe fitting along the first direction, or the refrigerant circularly flows between the backwashing pipe and the filter along the second direction.

Further, the fluid driving device further includes:

the two ends of the bypass pipe are respectively communicated with the first pipe fitting;

an ejector disposed on the bypass pipe and configured to urge the refrigerant entering from the inlet end of the ejector to flow out in the second direction; and

and the outlet valve is arranged at the outlet end of the ejector and is configured to controllably close the outlet end of the ejector when the refrigerant flows along the first direction so as to prevent the refrigerant from flowing into the outlet end of the ejector.

Further, the flow path switching device includes:

the first valve is arranged at the end part of the first pipe fitting;

a second valve provided at an end of the second pipe;

a third valve disposed in the backwash tube adjacent the first end thereof;

a fourth valve disposed in the backwash pipe adjacent the second end thereof;

a fifth valve disposed on the first tube between the outlet end of the bypass tube and the first end of the backwash tube; and is

Is configured to:

when the pressure difference between the front and the back of a filter element of the filter is smaller than or equal to a preset pressure difference threshold value, the first valve, the second valve and the fifth valve are controlled to be opened, and the third valve and the fourth valve are controlled to be closed, so that the refrigerant flows into the filter through the second pipe fitting and flows out of the first pipe fitting along the first direction; or

When the pressure difference between the front and the rear of a filter element of the filter is larger than a preset pressure difference threshold value, the first valve, the second valve and the fifth valve are controlled to be closed, and the third valve and the fourth valve are controlled to be opened, so that the refrigerant circularly flows among the backwashing pipe, the bypass pipe and the filter along the second direction.

Furthermore, the backwash pipe is provided with a pipe wall which protrudes outwards along the radial direction of the backwash pipe to form a sewage storage tank, and impurities carried by the refrigerant are deposited in the sewage storage tank when the refrigerant flows through the backwash pipe.

Further, the sump is located between the third valve and the fourth valve; and is

And the bottom of the sewage storage tank is connected with a sewage discharge pipe, the sewage discharge pipe is provided with a sewage discharge valve for controlling the opening and closing of the sewage discharge pipe, and the sewage discharge valve is controlled to be opened after the third valve and the fourth valve are closed so as to discharge impurities precipitated in the sewage storage tank.

Further, the dirt storage tank is positioned below the backwashing pipe so as to ensure that the refrigerant enters the dirt storage tank when flowing through the backwashing pipe.

Further, the filter structure further comprises:

a differential pressure sensor disposed on the filter and configured to detect a differential pressure across a filter element of the filter.

Furthermore, the filter element comprises a first fixing frame, a supporting spring, a second fixing frame, a drying agent layer, a filter screen and a third fixing frame which are sequentially arranged along the first direction, and two ends of the supporting spring are respectively connected with the first fixing frame and the second fixing frame.

In particular, the present invention provides a refrigeration system comprising a filter structure according to any one of the above.

The filter is arranged in a refrigerant flow path of a refrigeration system to filter refrigerant flowing through an inner filter element in a first direction, the fluid driving device is adjacent to the filter and can promote the refrigerant to flow through the filter in a second direction, and when the pressure difference sensor detects that the pressure difference of the inner filter element of the filter is greater than a preset pressure difference threshold value, the ejector is started to flush the inner filter element of the filter.

Furthermore, the back flushing pipe is provided with a pipe wall which protrudes outwards along the radial direction of the back flushing pipe to form a dirt storage tank, and when a refrigerant flows through the back flushing pipe, impurities carried by the refrigerant are deposited in the dirt storage tank to prevent secondary pollution of the filter element; and the dirt storage tank is positioned between the third valve and the fourth valve, after the back flushing is finished, the third valve and the fourth valve are closed, the back flushing pipe is isolated from the filter, the pressure of the refrigerant is relieved when the refrigerant normally flows, collected impurities are discharged to the outside by opening the dirt discharge valve, the reduction of the normal pressure of the refrigerant is avoided, and the stability of the refrigeration system in normal operation is kept.

The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the invention will be described in detail hereinafter, by way of illustration and not limitation, with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

FIG. 1 is a schematic diagram of a refrigeration system according to one embodiment of the present invention;

fig. 2 is a schematic view illustrating a filter structure when a refrigerant flows in a first direction according to an embodiment of the present invention;

fig. 3 is a schematic view of a filter structure when a refrigerant flows in a second direction according to an embodiment of the invention;

FIG. 4 is a control schematic block diagram of a filter structure according to one embodiment of the present invention.

Detailed Description

Referring to fig. 1, fig. 1 is a schematic diagram of a refrigeration system according to an embodiment of the invention. The present invention provides a refrigeration system 10, which can be applied to various refrigeration equipments, such as air conditioners, freezing and refrigerating apparatuses, etc., and for more clearly describing the structure and working principle of the present invention, the refrigeration system 10 will be described herein as an example of the application to the freezing and refrigerating apparatus. It should be noted that the application environment of the refrigeration system is not limited in any way.

In some embodiments, the refrigeration system 10 may be a refrigeration system comprised of a compressor 110, a condenser 120, a throttling device, an evaporator 130, and the like.

The compressor 110 is a power of a refrigeration cycle, and increases pressure and temperature of refrigerant vapor by compression, creating a condition for transferring heat of the refrigerant vapor to an external environment medium, i.e., compressing low-temperature and low-pressure refrigerant vapor to a high-temperature and high-pressure state, so that air or water at normal temperature can be used as a cooling medium to condense the refrigerant vapor.

The condenser 120 is a heat exchange device, and takes away heat of high-temperature and high-pressure refrigerant vapor from the compressor by using the environment, so that the high-temperature and high-pressure refrigerant vapor is cooled and condensed into refrigerant liquid with high pressure and normal temperature. The refrigerant liquid with high pressure and normal temperature is changed into a low-temperature and low-pressure refrigerant through the throttling device, so that the pressure of the refrigerant liquid is reduced, and the temperature of the refrigerant liquid is reduced.

The throttling means is also a heat exchange device. The throttled low-temperature and low-pressure refrigerant liquid is evaporated (boiled) in the refrigerant liquid to form steam, and the steam absorbs heat in the storage room to lower the temperature of the storage room, so that the aim of freezing and refrigerating food is fulfilled.

The evaporator 130 is configured to provide cooling energy directly or indirectly to the storage compartment of the cold storage device. For example, in a compression-type direct-cooling refrigerator, the evaporator 130 may be disposed outside or inside the rear wall surface of the inner container of the refrigerator. In the compression type air-cooled refrigerator, an evaporator chamber is further arranged in the refrigerator body and is communicated with the storage compartment through an air path system, an evaporator is arranged in the evaporator chamber, and a fan is arranged at an outlet of the evaporator chamber so as to perform circulating refrigeration on the storage compartment.

The refrigerant is also called as refrigerant, and is a medium substance for completing energy conversion in various refrigeration systems. It extracts heat from the cooled object at a low temperature and then transfers it to cooling water or air at a higher temperature. For example, in the freezing and refrigerating device, the refrigerant at the evaporator 130 absorbs the heat of the air in the storage compartment and transfers the part of the heat to the condenser for cooling.

As described in the background section, substances and impurities harmful to equipment in the processes of maintenance, assembly, refrigerant filling and the like of a refrigeration system often enter a flow path of the refrigeration system, such as water vapor in air, welding slag and the like, and these substances affect the safety and the service life of the refrigeration system, for example, the refrigerant is hydrolyzed after meeting water to generate acidic substances, corrosion is generated on the wall of a metal pipe, and large-particle impurities may cause pipe blockage and the like. In order to overcome the defects, a filter for filtering impurities is arranged in a refrigeration system in the related art, but after the refrigeration system runs for a long time, a filter screen is easy to block, and the heat exchange efficiency is influenced.

Referring to fig. 2 and 3, fig. 2 is a schematic diagram illustrating a filter structure when a refrigerant flows in a first direction according to an embodiment of the present invention, and fig. 3 is a schematic diagram illustrating a filter structure when a refrigerant flows in a second direction according to an embodiment of the present invention. In order to overcome the above-mentioned drawbacks of the prior art. The present application provides a filter structure that can achieve periodic cleaning of a filter, which includes a filter 200 and a fluid driving device 300.

The filter 200 is disposed in a refrigerant flow path of the refrigeration system 10 for filtering refrigerant flowing through an inner filter element thereof in a first direction 212, and the fluid driving device 300 is adjacent to the filter 200 and configured to controllably urge the refrigerant to flow through the filter 200 in a second direction 214 opposite to the first direction 212 at a flow rate above a predetermined flow rate threshold to flush the inner filter element of the filter 200.

In this embodiment, the first direction 212 refers to a flow direction of the refrigerant from the refrigerant inlet 232 to the refrigerant outlet 234 of the filter 200 during the normal operation of the refrigeration system 10, and the second direction 214 is opposite to the first direction 212, i.e., the flow direction of the refrigerant from the refrigerant inlet 232 to the refrigerant inlet 234 of the filter 200.

The refrigerant flows through the filter 200 in the first direction 212, and impurities in the refrigerant are filtered by the filter element inside the filter. When the refrigeration system 10 is continuously operated, a large amount of impurities attached to the filter element may increase a pressure difference between the front and the rear of the filter 200, reduce a refrigerant flow rate, and further reduce refrigeration efficiency.

In some specific implementations of the present application, the fluid driving device 300 may be adjacent to the refrigerant outlet 234 of the filter 200, and when the filter element of the filter 200 is attached with more impurities, the fluid driving device 300 can cause the refrigerant to change direction, and flush the filter element along the second direction 214 at a flow rate above a predetermined flow rate threshold, especially flush the surface of the filter element near the refrigerant inlet 232.

The flow rate above the preset flow rate threshold may be a continuous flow rate or a pulsed flow rate. And the preset flow rate threshold is a set value, and can be specifically configured according to factors such as the structure and strength of the filter 200, so that the requirement for flushing impurities attached to the filter element is met, and the safety of the filter 200 is not affected. It should be noted that the specific value of the preset flow rate threshold is not particularly limited in the present application.

In some embodiments of the present disclosure, the first pipe 240 is formed at the refrigerant outlet 234, and the second pipe 250 is formed at the refrigerant inlet 232; the filter structure further comprises a backwash pipe 400 and a flow path switching device.

The first end 410 of the backwash pipe 400 communicates with the first pipe 240, the second end 420 of the backwash pipe 400 communicates with the second pipe 250, and the refrigerant that is arranged to flush the filter 200 in the second direction 214 circulates between the backwash pipe 400 and the filter 200.

In this embodiment, the first end 410 of the backwash pipe 400 may be understood as a connection port of the backwash pipe 400 and the first pipe 240, and the second end 420 of the backwash pipe 400 may be understood as a connection port of the backwash pipe 400 and the second pipe 250. However, it should be noted that the first end 410 and the second end 420 are only used for convenience of describing and understanding the technical solution of the present invention, and do not indicate or imply that the indicated device or component must have a specific orientation, and thus, should not be construed as limiting the present invention.

The flow path switching device is configured to controllably switch the refrigerant flow path such that the refrigerant flows into the filter 200 through the second pipe 250 and flows out of the first pipe 240 in the first direction 212, or the refrigerant circulates between the backwash pipe 400 and the filter 200 in the second direction 214. When the fluid driving device 300 causes the refrigerant to flow in the reverse direction, a circulation loop is formed between the back flushing pipe 400 and the filter 200, in which the refrigerant flows in the second direction 214, so that the refrigerant flushing the filter element flows in the reverse direction only in the circulation loop, and the refrigerant flow in the entire refrigeration system 10 is prevented from being influenced.

In some embodiments of the present application, the fluid drive device 300 further comprises a bypass tube 310, an injector 320, and an outlet valve 330. Both ends of the bypass pipe 310 are respectively communicated with the first pipe 240, the ejector 320 is disposed on the bypass pipe 310 and configured to force the refrigerant entering from the inlet end of the ejector 320 to flow out in the second direction 214, and the outlet valve 330 is disposed at the outlet end of the ejector 320 and configured to controllably close the outlet end of the ejector 320 when the refrigerant flows in the first direction 212, thereby preventing the refrigerant from flowing in from the outlet end of the ejector 320.

The ejector 320 is a vacuum obtaining device for transferring energy and mass by using fluid, and the fluid with certain pressure is ejected through nozzles symmetrically and uniformly distributed with certain side slopes and is converged on one focus. The ejector 320 has the advantages of small volume, light weight, compact structure, high fluid injection speed and the like, and is suitable for the refrigeration system 10 of the present application.

In order to prevent the refrigerant of the refrigeration system 10 from affecting the ejector 320 when flowing normally in the first direction 212, the fluid driving apparatus of the present embodiment is provided with the bypass pipe 310 and the outlet valve 330. The outlet valve 330 may be controllably closed when the refrigerant normally flows in the first direction 212 such that the bypass pipe 310 is not conducted with the first pipe member 240 during the normal operation, and the outlet valve 330 may be controllably opened when backflushing and after the injector 320 is activated to form a circulation loop at the filter 200, the backflush pipe 400, and the bypass pipe 310.

The flow path switching device can switch the flow path of the refrigerant, so that the refrigerant does not enter the backwash pipe 400 but directly flows out of the first pipe 240 when flowing along the first direction 212; or the refrigerant is flushed back in the second direction 214, the first pipe 240 and the second pipe 250 are closed to form an independent circulation flushing loop, so as to avoid affecting the whole refrigeration system 10.

Specifically, the flow path switching device includes a first valve 510, a second valve 520, a third valve 530, a fourth valve 540, and a fifth valve 550.

The first valve 510 is disposed at an end of the first pipe member 240, and a port thereof opposite to the first pipe member 240 may be connected to a condensation duct 20 or other piping of the refrigeration system 10. The second valve 520 is provided at an end of the second pipe member 250, and a port thereof opposite to the second pipe member 250 may be connected to the condensation duct 20 or other piping of the refrigeration system 10. Third valve 530 is disposed in backwash tube 400 adjacent first end 410 thereof. A fourth valve 540 is disposed in the backwash tube 400 near the second end 420 thereof. A fifth valve 550 is disposed on the first pipe member 240 between the outlet end of the bypass pipe 310 and the first end 410 of the backwash pipe 400.

The first valve 510, the second valve 520, and the fifth valve 550 are used for controlling the opening and closing of the first pipe 240 and the second pipe 250, the third valve 530 and the fourth valve 540 are used for controlling the communication and closing of the backwash pipe 400 with the first pipe 240 and the second pipe 250, respectively, and the first valve 510, the second valve 520, the third valve 530, the fourth valve 540, and the fifth valve 550 can be engaged with each other by opening and closing to switch the flow path of the refrigerant.

Referring to fig. 2, when the pressure difference across the filter element of the filter 200 is less than or equal to the predetermined pressure difference threshold, the first valve 510, the second valve 520, and the fifth valve 550 are controlled to be opened, and the third valve 530 and the fourth valve 540 are controlled to be closed, and the refrigerant flows from the second pipe 250 into the refrigerant inlet 232 along the first direction 212, passes through the filter element of the filter 200 to filter impurities, and finally flows into the first pipe 240 through the refrigerant outlet 234, and then enters the condenser pipe 20 or other pipes of the refrigeration system 10 connected to the first pipe 240. And since the third valve 530 and the fourth valve 540 are controlled to be closed, when the refrigerant flows in the first direction 212, the refrigerant does not enter the back-flushing pipe 400, and the refrigerant of the refrigeration system 10 is ensured to normally operate.

Referring to fig. 3, when the pressure difference across the filter element of the filter 200 is greater than the predetermined pressure difference threshold, the first valve 510, the second valve 520, and the fifth valve 550 are controllably closed, and the third valve 530 and the fourth valve 540 are controllably opened, such that an independent circulation loop is formed between the filter 200, the bypass pipe 310, and the back-flushing pipe 400. When the ejector 320 is activated, the flow direction of the refrigerant is changed to reversely flush the filter element of the filter 200, and the refrigerant flows out of the refrigerant inlet 232, enters the second pipe 250, enters the backwash pipe 400 from the port where the second pipe 250 is connected with the backwash pipe 400, and then directly flows into the inlet end of the ejector 320 through the first pipe 240, thereby completing the circulation.

In this embodiment, the refrigeration system 10 can determine whether the filter 200 needs to be cleaned by detecting the pressure difference across the filter element of the filter 200 in real time. A greater differential pressure across the filter element of filter 200 indicates a greater degree of clogging of the filter element. And the preset pressure difference threshold may be a set value, when the detected front-back pressure difference value of the filter element of the filter 200 is greater than the preset pressure difference threshold, the first valve 510, the second valve 520 and the fifth valve 550 are closed, the third valve 530 and the fourth valve 540 are opened, and a flushing loop is established to flush the filter element.

In some embodiments of the present application, the refrigeration system 10 further includes a differential pressure sensor 610 disposed on the filter 200 and configured to detect a differential pressure across a filter element of the filter 200. Differential pressure sensor 610 is a sensor used to measure the difference between two pressures, and is typically used to measure the pressure difference across a device or component. In this embodiment, two pressure ports can be vertically connected to two ends of the filter element to detect the differential pressure between the front and rear ends of the filter element in real time.

In some embodiments of the present application, the backwash pipe 400 has a pipe wall protruding radially outward therefrom to form a sump 430, and is configured to deposit impurities carried by the refrigerant into the sump 430 when the refrigerant flows through the backwash pipe 400.

After the back flushing of the refrigerant, the impurities attached to the filter element enter the back flushing pipe 400 along with the refrigerant, and are left in the dirt storage tank 430 in a physical sedimentation mode in the process of flowing through the dirt storage tank 430 so as to prevent secondary pollution to the filter element.

The soil storage tank 430 is positioned between the third valve 530 and the fourth valve 540, a soil discharge pipe 440 is connected to the bottom of the soil storage tank 430, a soil discharge valve 450 for controlling the opening and closing of the soil discharge pipe 440 is provided, and the soil discharge valve 450 is configured to be controllably opened to discharge the impurities settled in the soil storage tank 430 after the third valve 530 and the fourth valve 540 are closed.

After the back flushing is finished, the third valve 530 and the fourth valve 540 are closed, the back flushing pipe 400 is isolated from the filter 200, the pressure of the refrigerant is relieved when the refrigerant normally flows, the back flushing pipe 400 is in an independent closed environment at the moment, collected impurities can be discharged to the outside by opening the blowdown valve 450, and the reduction of the normal pressure of the refrigerant is avoided.

In some preferred embodiments, sump 430 is located below backwash tube 400 such that the refrigerant gravitates into sump 430 as it flows through backwash tube 400 to improve collection efficiency.

Referring to fig. 4, fig. 4 is a control schematic block diagram of a refrigeration system according to an embodiment of the present invention. In some embodiments of the present application, the refrigeration system 10 further includes a main controller 600, and the first valve 510, the second valve 520, the third valve 530, the fourth valve 540, the fifth valve 550, the outlet valve 330, and the blowdown valve 450 may be configured as any one of an electric shut-off valve and a pneumatic shut-off valve, and the main controller 600 receives a differential pressure signal across the filter element of the filter 200 acquired by the differential pressure sensor 610 in real time, compares the differential pressure signal with a preset differential pressure threshold, and sends an execution command to the first valve 510, the second valve 520, the third valve 530, the fourth valve 540, the fifth valve 550, the outlet valve 330, the blowdown valve 450, and the ejector 320 to open or close the valves.

In some embodiments of the present application, the filter element includes a first fixing frame 262, a supporting spring 222, a second fixing frame 264, a desiccant layer 224, a filter screen 226, and a third fixing frame 266, which are sequentially arranged along the first direction 212, wherein two ends of the supporting spring 222 are respectively connected to the first fixing frame 262 and the second fixing frame 264.

The first, second and third holders 262, 264, 266 serve to hold the support spring 222, the desiccant bed 224 and the filter screen 226. The desiccant layer 224 may adsorb water in the refrigerant, and the filter 226 may be used to filter other impurities in the refrigerant. Of course, the filter element may have other components, which are not described herein so as not to obscure the invention of the present application.

Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been illustrated and described in detail herein, many other variations or modifications consistent with the principles of the invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be understood and interpreted to cover all such other variations or modifications.