Two-stage compression system and refrigeration apparatus

Abstract

The application relates to the air conditioning technical field, and particularly provides a two-stage compression system and a refrigeration equipment, which aims to solve the problems of aerodynamic noise caused by excessively long inter-stage pipe length and insufficient gas-liquid separation of an economizer. To this end, the two-stage compression system comprises: a compressor having a first compression part and a second compression part; and an economizer comprising a shell having a cavity and a separation device arranged in the cavity, the separation device being capable of allowing a gas-phase refrigerant to pass through and blocking and gathering liquid drops in the gas-phase refrigerant, the shell being provided with a gas inlet and a gas outlet corresponding to the gas cavity and a liquid inlet and a liquid outlet corresponding to a liquid cavity; a first refrigerant pipeline being connected between a gas outlet of the first compression part and the gas inlet; and a second refrigerant pipeline being connected between the gas outlet and a gas inlet of the second compression part. The application can reduce the length of the connecting pipeline of the compressor and the economizer and improve the separation efficiency of the gas-liquid two-phase refrigerant of the economizer.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, specifically providing a two-stage compression system and a refrigeration device. Background Technology

[0002] Currently, with the development of air conditioning technology, the energy efficiency of air conditioners has gradually improved. While providing people with a comfortable indoor environment, it also reduces carbon emissions, which is in line with the concept of sustainable development. In air conditioning systems, the energy-saving device (i.e., the economizer) is mainly used to replenish gas to the compressor and increase the subcooling of the refrigerant, thereby improving the heat exchange efficiency of the liquid refrigerant and thus improving the overall energy efficiency of the air conditioning system.

[0003] In related technologies, such as Figure 1 As shown, the economizer is located between the condenser and the evaporator, and the two-stage compressor is connected to the gaseous refrigerant outlet of the economizer via an interstage pipe. Since the economizer and the compressor are two independent modules, the gaseous refrigerant outlet of the economizer is connected to the compressor via a lengthy interstage pipe. The economizer contains a perforated baffle to separate the gaseous and liquid refrigerant.

[0004] However, the lengthy interstage tubing can cause significant flow resistance and aerodynamic noise during the flow of gaseous refrigerant. Furthermore, the gaseous refrigerant, after gas-liquid separation through the through-holes, may contain liquid refrigerant, potentially causing liquid slugging in the compressor and affecting its safety performance. Utility Model Content

[0005] This application aims to solve the above-mentioned technical problems, namely, to solve the aerodynamic noise problem caused by excessively long interstage tubes and the problem of insufficient gas-liquid separation in the economizer.

[0006] In a first aspect, this application provides a two-stage compression system, comprising: a compressor having a first compression section and a second compression section; an economizer arranged close to the compressor, including a housing with a cavity and a separation device disposed within the cavity, the separation device being configured to allow gaseous refrigerant to pass through and to block and collect liquid droplets in the gaseous refrigerant, the housing having a gas inlet and a gas outlet corresponding to the gas cavity, and a liquid inlet and a liquid outlet corresponding to the liquid cavity, wherein the gas-liquid two-phase refrigerant enters the housing through the liquid inlet; a first refrigerant pipeline connected to the outlet of the first compression section and the gas inlet; and a second refrigerant pipeline connected to the gas outlet and the inlet of the second compression section.

[0007] By adopting the above technical solution, by setting the first refrigerant pipeline directly connected to the outlet and inlet of the first compression section, and setting the second refrigerant pipeline directly connected to the outlet and inlet of the second compression section, the redundant pipeline setup between the first and second compression sections is reduced, making the compressor and economizer an integrated module. This reduces the resistance and aerodynamic noise of the refrigerant during flow. At the same time, the separation device can separate the gas-liquid two-phase refrigerant flowing in through the liquid inlet. The liquid phase refrigerant drips back into the liquid chamber, while the gas phase refrigerant enters the gas chamber and mixes with the gas phase refrigerant that has been compressed by the first compression section flowing in through the gas inlet. This reduces the temperature of the refrigerant after the first stage of compression. The gas phase refrigerant then enters the second compression section through the gas outlet, reducing the compression work of the second compression section and improving the energy efficiency ratio of the two-stage compression system.

[0008] In an optional embodiment of the above-described two-stage compression system, the separation device is configured such that the wire mesh separation layer includes at least a first layer group and a second layer group arranged from top to bottom; the first layer group includes one or more layers of first wire mesh, and the second layer group includes one or more layers of second wire mesh; wherein the mesh aperture of the first wire mesh is larger than the mesh aperture of the second wire mesh.

[0009] Since the gaseous refrigerant moves upward from the liquid chamber to the gas chamber, the second wire mesh, which is closer to the liquid chamber, has a smaller mesh size than the first wire mesh. This allows for better interception and collection of droplets carried in the gaseous refrigerant, without affecting the flow of the gaseous refrigerant into the gas chamber.

[0010] In an optional embodiment of the above-mentioned two-stage compression system, the wire mesh separation layer further includes a porous media layer disposed between the first layer group and the second layer group, wherein the porous media layer has a plurality of interconnected sieve holes defined inside.

[0011] By setting a porous medium layer, impurities in the refrigerant can be adsorbed, and liquid droplets carried in the gaseous refrigerant can be captured, thus ensuring that the refrigerant flowing into the gas chamber is all gaseous refrigerant.

[0012] In an optional embodiment of the above-described two-stage compression system, the wire mesh separation layer is constructed as a wavy wire mesh.

[0013] By constructing the wire mesh separation layer as a corrugated wire mesh, the surface area effectively used for separating the gas-liquid two-phase refrigerant can be increased, thereby improving the filtration capacity. Furthermore, the corrugated wire mesh structure helps to alter the refrigerant's flow path, promoting inertial collisions and coalescence of droplets, effectively intercepting droplets, and improving the separation efficiency of the gaseous refrigerant and its carried droplets.

[0014] In an optional implementation of the above-mentioned two-stage compression system, the distance between adjacent crests and troughs of the corrugated wire mesh is 10 mm; and / or, the distance between adjacent crests and troughs of the corrugated wire mesh is 13 mm.

[0015] This further optimizes the separation effect of the corrugated wire mesh. Specifically, setting the distance between adjacent crests and troughs to 10mm ensures that droplets are more likely to collide with and coalesce on the wire mesh surface due to inertia during flow, thereby improving droplet interception efficiency. Meanwhile, the 13mm distance between adjacent crests and troughs extends the residence time of the refrigerant within the wire mesh separation layer while ensuring smooth gaseous refrigerant flow, resulting in more thorough gas-liquid separation, further reducing the amount of droplets entrained in the gaseous refrigerant, and improving the stability and safety of the two-stage compression system.

[0016] In an optional embodiment of the above-mentioned two-stage compression system, the filter density of the wire mesh separation layer is 180 kg / m to 220 kg / m.

[0017] In this way, sufficient separation efficiency of the gaseous refrigerant and its carried droplets can be ensured while avoiding excessive resistance to the refrigerant flow. Furthermore, a proper selection of filter mesh density can effectively balance the mechanical strength and service life of the wire mesh separation layer, ensuring good performance during long-term operation.

[0018] In an optional embodiment of the above-mentioned two-stage compression system, the separation device divides the cavity into an upper and lower distributed gas cavity and a liquid cavity, and the second refrigerant pipeline has an extension section extending into the gas cavity, and the inlet end of the extension section is provided with a gas-liquid separator.

[0019] By installing a gas-liquid separator at the inlet end of the extension section, droplets generated after the gaseous refrigerant separated by the wire mesh separation layer mixes with the gaseous refrigerant compressed by the first compression section can be prevented from entering the second compression section, thus ensuring the safety and compression efficiency of the second compression section.

[0020] In an optional implementation of the above-mentioned two-stage compression system, a wire mesh separation layer is also provided at the inlet end of the second refrigerant pipeline, and the wire mesh separation layer abuts against the inlet end of the second refrigerant pipeline.

[0021] In this way, droplets can be prevented from entering the second compression section, ensuring the safety and compression efficiency of the second compression section.

[0022] In an optional embodiment of the above-described two-stage compression system, a sleeve is provided around the extension section. One end of the sleeve is open and communicates with the air chamber, while the other end of the sleeve is connected to the inlet end of the extension section. The sleeve contains multiple baffles, which are spaced apart along the length of the sleeve, with adjacent baffles arranged in a staggered manner.

[0023] In this way, the liquid droplets in the gaseous refrigerant flowing into the gas outlet can be separated.

[0024] In an optional embodiment of the above-mentioned two-stage compression system, a heating element is further included, disposed in the wire mesh separation layer, wherein the heating element is configured to heat the gaseous refrigerant passing through the wire mesh separation layer.

[0025] By setting up a heating element, the temperature of the gaseous refrigerant that has passed through the wire mesh separation layer can be appropriately increased, reducing the amount of droplets generated when this gaseous refrigerant mixes with the refrigerant compressed in the first compression section, thereby improving the safety of the two-stage compression system.

[0026] In an optional implementation of the above-mentioned two-stage compression system, a third refrigerant line is further included, connected to the liquid inlet; and a fourth refrigerant line is connected to the liquid outlet.

[0027] By setting up the third and fourth refrigerant lines, it is possible to introduce gas-liquid two-phase refrigerant into the shell and to export liquid refrigerant.

[0028] In an optional embodiment of the above-mentioned two-stage compression system, the third refrigerant line has a first bend extending into the liquid chamber, and the interior of the first bend is provided with a first throttling orifice plate; and / or, the fourth refrigerant line has a second bend extending into the liquid chamber, and the interior of the second bend is provided with a second throttling orifice plate; wherein the first throttling orifice plate and / or the second throttling orifice plate are double-layer orifice plates.

[0029] By installing a first throttling orifice plate in the first bend of the third refrigerant pipeline, the flow rate of liquid refrigerant entering the economizer can be controlled to ensure an appropriate liquid level in the housing. At the same time, it can cause some of the liquid refrigerant to flash into the gas phase, thereby increasing the amount of gas refrigerant flowing into the gas chamber.

[0030] By setting the second throttling orifice plate, the pressure of the liquid refrigerant flowing out of the liquid chamber can be further reduced, and to a certain extent, some of the liquid refrigerant can be flashed into the gas phase. This ensures the amount of liquid phase in the liquid chamber and the refrigerant flow rate at the liquid outlet, while increasing the amount of gas supplied to the second compressor to improve compression efficiency.

[0031] By configuring the first and / or second orifice plates as double-layer orifice plates, the flow and pressure changes of the refrigerant can be controlled more precisely, while reducing vibration and noise caused by the throttling process. The double-layer orifice plate design also effectively extends the service life of the first and / or second orifice plates, avoiding orifice wear or clogging problems caused by long-term use, thereby improving the stability and reliability of the system.

[0032] In an optional implementation of the above-mentioned two-stage compression system, the third refrigerant line further has a first external extension section, on which a first regulating valve is provided; and / or, the fourth refrigerant line further has a second external extension section, on which a second regulating valve is provided.

[0033] By setting the first regulating valve, the refrigerant flow rate in the third refrigerant pipeline can be controlled to ensure that the amount of liquid refrigerant in the liquid chamber is relatively sufficient.

[0034] By using the second regulating valve to control the refrigerant flow in the fourth refrigerant line, in conjunction with the first regulating valve, the amount of refrigerant in the liquid chamber can be further maintained to prevent cross-contamination.

[0035] Secondly, this application provides a refrigeration device, including the two-stage compression system as described above. Attached Figure Description

[0036] The preferred embodiments of this application are described below with reference to the accompanying drawings, in which:

[0037] Figure 1 This is a schematic diagram of the structure of a refrigeration system in the prior art;

[0038] Figure 2 This is a schematic diagram of a two-stage compression system provided in this application;

[0039] Figure 3 This is a schematic diagram of another two-stage compression system provided in this application.

[0040] Figure 4 This is a schematic diagram of the structure of a refrigeration device provided in this application;

[0041] Figure 5 This is a pressure-enthalpy diagram of an economizer provided in this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 100. Compressor; 110. First compression section; 120. Second compression section; 200. Economizer; 201. Gas chamber; 202. Liquid chamber; 210. Shell; 220. Wire mesh separation layer; 221. First layer group; 222. Second layer group; 223. Porous media layer; 310. First refrigerant line; 320. Second refrigerant line; 321. Extension section; 330. Third refrigerant line; 331. First bend section; 332. First external extension section; 340. Fourth refrigerant line; 341. Second bend section; 342. Second external extension section; 410. First orifice plate; 420. Second orifice plate; 510. First regulating valve; 520. Second regulating valve; 600. Condenser; 700. Evaporator. Detailed Implementation

[0044] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. In the following description, for ease of explanation, numerous details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other instances, well-known structures and apparatuses may be simplified for the sake of simplicity.

[0045] It should be noted that in the description of this application, the terms "center," "upper," "lower," "vertical," "inner," and "outer," which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0047] Firstly, combining Figures 2 to 5 As shown, this application provides a two-stage compression system, including a compressor 100, an economizer 200, a first refrigerant line 310, and a second refrigerant line 320. The compressor 100 has a first compression section 110 and a second compression section 120. The economizer 200 is arranged close to the compressor 100 and includes a housing 210 with a cavity and a separation device disposed within the cavity. The separation device divides the cavity into a gas cavity 201 and a liquid cavity 202 distributed vertically. The separation device is configured to allow gaseous refrigerant to pass through and to block and collect liquid droplets in the gaseous refrigerant. The housing 210 has a gas inlet and a gas outlet corresponding to the gas cavity 201, and a liquid inlet and a liquid outlet corresponding to the liquid cavity 202. The gas and liquid refrigerant enter the housing 210 through the liquid inlet. The first refrigerant line 310 is fixedly connected between the outlet of the first compression section 110 and the gas inlet. The second refrigerant line 320 is fixedly connected between the gas outlet and the inlet of the second compression section 120.

[0048] Optionally, the compressor 100 includes a compressor housing, and a first compression section 110 and a second compression section 120 are disposed inside the compressor housing. In this embodiment, the gaseous refrigerant undergoes primary compression in the first compression section 110 and then enters the second compression section 120 for secondary compression.

[0049] In this design, the economizer 200 and compressor 100 form an integrated compression system. The liquid inlet of compressor 100 allows for the input of a two-phase refrigerant (gas and liquid). After the two-phase refrigerant enters the liquid chamber 202, due to the density difference, the gaseous refrigerant moves upward to the gas chamber 201, while the liquid refrigerant drips downward to the bottom of the liquid chamber 202. Furthermore, since some liquid droplets are quite small, they can rise along with the gaseous refrigerant. Therefore, it is necessary to separate the droplets in the gaseous refrigerant.

[0050] Furthermore, a separation device is provided inside the housing 210 of the economizer 200. When droplets carried in the gaseous refrigerant pass through the separation device, they are captured and collected by the separation device, and the gaseous refrigerant moves upward into the gas chamber 201. After the small droplets gradually gather into large droplets, they fall to the bottom of the liquid chamber under the action of gravity and mix with the liquid refrigerant at the bottom of the liquid chamber.

[0051] Optionally, the refrigerant needs to be kept at a certain level in the liquid chamber 202. Therefore, the height of the wire mesh separation layer 220 should be at least higher than the maximum liquid level of the liquid refrigerant.

[0052] Optionally, the economizer 200 is arranged close to the compressor 100, and is located in the middle position between the outlet of the first compression section 110 and the inlet of the second compression section 120. In this way, the length of the first refrigerant line 310 and the second refrigerant line 320 can be reduced, the structural compactness of the two-stage compression system can be improved, and the aerodynamic noise generated when the gaseous refrigerant flows in the first refrigerant line 310 and the second refrigerant line 320 can be reduced, the flow resistance can be reduced, and the compression efficiency of the compressor 100 can be improved.

[0053] Optionally, the first refrigerant line 310 and the second refrigerant line 320 are directly welded between the compressor housing and the casing 210, so that the economizer 200 and the compressor 100 form an integrated modular two-stage compression system.

[0054] Alternatively, the compressor housing, the first refrigerant line 310, the second refrigerant line 320 housing 210, and the integral molding are also included.

[0055] In this design, the temperature of the gaseous refrigerant separated in the economizer 200 is lower than the temperature of the gaseous refrigerant formed after compression in the first compression section 110. The mixing of the two gaseous refrigerants lowers the temperature of the gaseous refrigerant entering the second compression section 120, thereby increasing the compression ratio of the second compression section 120. This not only enables supplemental gas supply to the compressor 100 but also improves the compression efficiency of the compressor 100.

[0056] In addition, combined Figure 5 As shown, the gas-liquid two-phase refrigerant entering the housing 210 through the liquid inlet in the economizer 200 has a larger contact area with the gas-phase refrigerant compressed in the first compression section 110. While replenishing the gas, it can also effectively cool the superheated gas after the first compression, reducing the temperature of the gas-phase refrigerant flowing to the second compression section 120, thereby... Figure 5 The isentropic line between points 2' and 4 on the theoretical cyclic pressure-enthalpy diagram shifts to the left, meaning point 2' moves to 2' and point 4 moves to 4'. The gaseous refrigerant is closer to saturation, reducing the power consumption of the second compression section 120. Experiments have shown that the two-stage compression system in this design can improve the system COP by at least 2.0%. Figure 5 In the diagram, the arrow indicates the direction of refrigerant flow; P k P is the condensing pressure of the condenser. m The pressure in the economizer is between the evaporation pressure and the condensation pressure; P o This is the evaporation pressure in the evaporator.

[0057] Alternatively, the separation device can be in the form of a gas-liquid filter, a baffle, or the like.

[0058] By adopting the above technical solution, by setting the first refrigerant pipeline directly connected to the outlet and inlet of the first compression section, and setting the second refrigerant pipeline directly connected to the outlet and inlet of the second compression section, the redundant pipeline setup between the first and second compression sections is reduced, making the compressor and economizer an integrated module. This reduces the resistance and aerodynamic noise of the refrigerant during flow. At the same time, the separation device can separate the gas-liquid two-phase refrigerant flowing in through the liquid inlet. The liquid phase refrigerant drips back into the liquid chamber, while the gas phase refrigerant enters the gas chamber and mixes with the gas phase refrigerant that has been compressed by the first compression section flowing in through the gas inlet. This reduces the temperature of the refrigerant after the first stage of compression. The gas phase refrigerant then enters the second compression section through the gas outlet, reducing the compression work of the second compression section and improving the energy efficiency ratio of the two-stage compression system.

[0059] In an optional embodiment of the above-described two-stage compression system, the separation device is configured as a wire mesh separation layer 220, which includes at least a first layer group 221 and a second layer group 222 arranged from top to bottom; the first layer group 221 includes one or more layers of first wire mesh, and the second layer group 222 includes one or more layers of second wire mesh; wherein the mesh aperture of the first wire mesh is larger than the mesh aperture of the second wire mesh.

[0060] Since the gaseous refrigerant moves upward from bottom to top from the liquid chamber 202 to the gas chamber 201, the mesh size of the second wire mesh, which is closer to the liquid chamber 202, is smaller than that of the first wire mesh. This allows for better interception and collection of droplets carried in the gaseous refrigerant, without affecting the flow of the gaseous refrigerant into the gas chamber.

[0061] Optionally, the multiple layers of first wire mesh in the first layer group 221 are arranged in an alternating manner, that is, the mesh openings of adjacent first wire meshes at least partially overlap; the multiple layers of second wire mesh in the second layer group 222 are arranged in an alternating manner, that is, the mesh openings of adjacent second wire meshes at least partially overlap.

[0062] Optionally, the mesh shape of the first wire mesh is round, rhomboid, rectangular, triangular, etc.; the mesh shape of the second wire mesh is round, rhomboid, rectangular, triangular, etc.

[0063] Optionally, the thickness of the screen separation layer 220 is 5 mm to 10 mm.

[0064] Optionally, the wire mesh separation layer 220 may further include at least a third layer group, which is disposed above the first layer group 221, and the mesh aperture of the third wire of the third layer group is smaller than the mesh aperture of the first wire mesh.

[0065] Alternatively, the first layer group 221 and the second layer group 222 are stacked sequentially from top to bottom.

[0066] Alternatively, the screen separation layer 220 may include multiple first or second layers arranged from top to bottom.

[0067] Alternatively, at least two sets of spaced wire mesh separation layers 220 may be provided to improve the separation effect of droplets in the gaseous refrigerant.

[0068] Optionally, a frame is provided around the circumference of the wire mesh separation layer 220. The frame is constructed in a U-shape, and the wire mesh separation layer 220 is inserted into the U-shaped opening. The frame is fixedly connected to the housing 210. This can improve the structural strength of the wire mesh separation layer 220 and the stability of the connection between the wire mesh separation layer 220 and the housing 210.

[0069] Optionally, multiple reinforcing ribs are provided at intervals along the length of the wire mesh separation layer 220 to improve the structural strength of the wire mesh separation layer 220.

[0070] Optionally, the wire mesh separation layer 220 is made of stainless steel wire.

[0071] Alternatively, the wire mesh separation layer 220 may be provided with a plurality of guide cones with tapered tips on the side near the liquid cavity 202, so as to puncture the droplets or to allow the liquid refrigerant collected on the wire mesh separation layer 220 to flow into the liquid cavity 202.

[0072] Alternatively, the separation device can be constructed with multiple spaced and staggered baffles to achieve the separation of gaseous and liquid refrigerants.

[0073] Alternatively, the separation device can also be a sleeve structure comprising an inner tube and an outer tube.

[0074] In the optional implementation of the above-mentioned two-stage compression system, combined with Figure 3 As shown, the wire mesh separation layer 220 further includes a porous media layer 223, which is disposed between the first layer group 221 and the second layer group 222. The porous media layer 223 has a plurality of interconnected sieve holes defined inside.

[0075] By setting a porous medium layer, impurities in the refrigerant can be adsorbed, and liquid droplets carried in the gaseous refrigerant can be captured, thus ensuring that the refrigerant flowing into the gas chamber is all gaseous refrigerant.

[0076] Optionally, the porous media layer includes porous graphene. Porous graphene has excellent sound absorption capabilities, thus reducing the ejection noise generated when the gas-liquid two-phase refrigerant flows into the cavity. The porous graphene contains multiple sieve pores, which are randomly connected in an irregular manner, or sequentially connected, forming multiple interconnected channels for the flow of the gas phase fluid. Optionally, the pore sizes of the multiple sieve pores are not uniformly distributed. Optionally, the pore sizes of the multiple sieve pores can also be the same. Optionally, the pore sizes of the sieve pores are arranged from largest to smallest from the side closer to the gas cavity 201 to the side closer to the liquid cavity 202. This arrangement helps to improve the separation efficiency of the porous media layer.

[0077] Optionally, the porous media layer includes copper foam. Foamed metal materials have a low specific gravity, a large specific surface area, and a porosity often exceeding 90%, with pore diameters reaching the millimeter level, while also possessing certain strength and rigidity.

[0078] Alternatively, a porous media layer may not be provided.

[0079] In an optional embodiment of the above-described two-stage compression system, the wire mesh separation layer 220 is configured as a wavy wire mesh.

[0080] By constructing the wire mesh separation layer 220 as a corrugated wire mesh, the surface area effectively used for separating the gas-liquid two-phase refrigerant can be increased, thereby improving the filtration capacity. In addition, the corrugated wire mesh structure helps to change the flow path of the refrigerant, thereby promoting the inertial collision and coalescence of droplets, effectively intercepting droplets, and improving the separation efficiency of the gas phase refrigerant and the carried droplets.

[0081] Optionally, the screen separation layer 220 is configured to be wavy in at least one direction. Specifically, the screen separation layer 220 is configured to be wavy in its length direction; and / or, the screen separation layer 220 is configured to be wavy in its width direction.

[0082] Optionally, the wire mesh separation layer 220 includes a first wire and a second wire arranged in a cross configuration, with the first wire arranged at an angle relative to the length direction of the wire mesh separation layer 220. The wire mesh separation layer 220 is configured to be wavy in the extension direction of the first wire; and / or, the wire mesh separation layer 220 is configured to be wavy in the extension direction of the second wire.

[0083] Alternatively, the wire mesh separation layer 220 is configured as a flat plate.

[0084] In an optional implementation of the above-mentioned two-stage compression system, the distance between adjacent crests and troughs of the corrugated wire mesh is 10 mm; and / or, the distance between adjacent crests and adjacent troughs of the corrugated wire mesh is 13 mm.

[0085] This further optimizes the separation effect of the corrugated wire mesh. Specifically, setting the distance between adjacent crests and troughs to 10mm ensures that droplets are more likely to collide with and coalesce on the wire mesh surface due to inertia during flow, thereby improving droplet interception efficiency. Simultaneously, the 13mm distance between adjacent crests and troughs extends the residence time of the refrigerant within the wire mesh separation layer 220 while ensuring smooth flow of the gaseous refrigerant, resulting in more thorough gas-liquid separation, further reducing the amount of droplets entrained in the gaseous refrigerant, and improving the stability and safety of the two-stage compression system.

[0086] In an optional embodiment of the above-mentioned two-stage compression system, the filter density of the wire mesh separation layer 220 is 180 kg / m to 220 kg / m.

[0087] In this way, sufficient separation efficiency of the gaseous refrigerant and its carried droplets can be ensured while avoiding excessive resistance to the flow of the refrigerant. In addition, the appropriate selection of filter density can effectively balance the mechanical strength and service life of the wire mesh separation layer 220, ensuring good performance during long-term operation.

[0088] Alternatively, the filter density of the wire mesh separation layer 220 can be determined based on actual experimental data.

[0089] In an optional embodiment of the above-mentioned two-stage compression system, the second refrigerant line 320 has an extension section 321 extending into the gas chamber 201, and the inlet end of the extension section 321 is provided with a gas-liquid separator.

[0090] By providing a gas-liquid separator at the inlet end of the extension section 321, droplets generated after the gaseous refrigerant separated by the wire mesh separation layer 220 mixes with the gaseous refrigerant compressed by the first compression section 110 can be prevented from entering the second compression section 120, thus ensuring the safety and compression efficiency of the second compression section 120.

[0091] Since the temperature of the gaseous refrigerant passing through the wire mesh separation layer 220 is lower than the temperature of the gaseous refrigerant flowing out of the exhaust port of the first compression section 110, some droplets may be generated after the two gaseous refrigerants are mixed. In order to prevent these droplets from entering the second compression section 120, a gas-liquid separator is provided at the inlet end of the extension section 321.

[0092] Optionally, the gas-liquid separator can be the aforementioned wire mesh separation layer, or other gas-liquid separators.

[0093] Alternatively, a gas-liquid separator may not be provided.

[0094] Alternatively, the extension segment 321 may not be provided.

[0095] In an optional implementation of the above-mentioned two-stage compression system, a wire mesh separation layer is also provided at the inlet end of the second refrigerant pipeline, and the wire mesh separation layer abuts against the inlet end of the second refrigerant pipeline.

[0096] In this way, droplets can be prevented from entering the second compression section, ensuring the safety and compression efficiency of the second compression section.

[0097] In an optional embodiment of the above-mentioned two-stage compression system, a sleeve is provided around the extension section 321. One end of the sleeve is open and communicates with the air chamber 201, and the other end of the sleeve is connected to the inlet end of the extension section 321. The sleeve contains multiple baffles, which are spaced apart along the length of the sleeve, and adjacent baffles are arranged in a staggered manner.

[0098] In this way, the liquid droplets in the gaseous refrigerant flowing into the gas outlet can be separated.

[0099] In an optional embodiment of the above-described two-stage compression system, a heating element is also included. The heating element is disposed in the wire mesh separation layer 220 and is configured to heat the gaseous refrigerant passing through the wire mesh separation layer 220.

[0100] By setting up the heating element, the temperature of the gaseous refrigerant passing through the wire mesh separation layer 220 can be appropriately increased, reducing the amount of droplets generated when this gaseous refrigerant mixes with the refrigerant compressed by the first compression section 110, thereby improving the safety of the two-stage compression system.

[0101] Optionally, the heating power of the heating element can be controlled.

[0102] Alternatively, a temperature detection device is provided on the wire mesh separation layer 220. When the temperature detected by the temperature detection device is greater than or equal to a first preset value, the heating element is controlled to stop heating. When the temperature detected by the temperature detection device is less than or equal to a second preset value, the heating element is controlled to start operating to release heat.

[0103] Specifically, the heating element is located in the second layer group or in the first layer group.

[0104] Optionally, the heating element includes an electric heating wire. Electric heating wires are readily available, have a fast heating speed, and high heating efficiency, enabling rapid heating of liquid phase fluid mixed in with gaseous fluid.

[0105] Alternatively, the heating element includes a heating probe. The heating probe is inserted inside the wire mesh separation layer 220. The heating probe includes a heating rod, which is covered by a heating outer shell.

[0106] Alternatively, no heating element may be provided.

[0107] In an optional implementation of the aforementioned two-stage compression system, a third refrigerant line 330 and a fourth refrigerant line 340 are also included. The third refrigerant line 330 is connected to the liquid inlet; the fourth refrigerant line 340 is connected to the liquid outlet.

[0108] By setting up the third refrigerant line 330 and the fourth refrigerant line 340, it is possible to introduce gas-liquid two-phase refrigerant into the shell 210 and to export liquid refrigerant.

[0109] Optionally, the third refrigerant line 330 is also connected to the condenser 600, and the fourth refrigerant line 340 is also connected to the evaporator 700. The first orifice plate 410 can restrict the flow of refrigerant, causing partial evaporation of the refrigerant when the pressure drops, thereby absorbing heat and lowering the temperature. This helps ensure that the refrigerant has reached a certain degree of superheat before entering the fourth refrigerant line 340 or the evaporator 700, thus improving system performance.

[0110] Alternatively, a throttle valve may be installed on the third refrigerant line 330 outside the economizer 200.

[0111] In an optional embodiment of the above-mentioned two-stage compression system, the third refrigerant line 330 has a first bend section 331 extending into the liquid chamber 202, and the interior of the first bend section 331 is provided with a first throttling orifice plate 410; and / or, the fourth refrigerant line 340 has a second bend section 341 extending into the liquid chamber 202, and the interior of the second bend section 341 is provided with a second throttling orifice plate 420.

[0112] The first orifice plate 410 and / or the second orifice plate 420 are double-layer orifice plates.

[0113] The first throttling orifice plate 410 installed in the first bend of the third refrigerant pipeline 330 can control the flow rate of liquid refrigerant entering the economizer 200, ensure that there is an appropriate liquid level in the housing 210, and at the same time enable part of the liquid refrigerant to flash into the gas phase, so as to increase the flow of gas refrigerant to the gas chamber 201.

[0114] Optionally, the first throttling orifice plate 410 can be subjected to detailed testing and matching during the testing of the two-stage compression system to ensure the reliability of the two-stage compression system during operation.

[0115] By setting the second throttling orifice plate 420, the pressure of the liquid refrigerant flowing out of the liquid chamber 202 can be further reduced, and to a certain extent, some of the liquid refrigerant can be flashed into the gas phase. While ensuring the amount of liquid refrigerant in the liquid chamber 202 and the flow rate of the refrigerant flowing out of the liquid outlet, the amount of gas supplied to the second compression section 120 can be increased to improve the compression efficiency.

[0116] The second orifice plate 420 further reduces the refrigerant pressure and controls the refrigerant flow rate to ensure proper evaporation of the refrigerant before it enters the evaporator 700. This helps maintain appropriate refrigerant flow and pressure to meet the system's cooling requirements. By properly designing and installing the first orifice plate 410 and the second orifice plate 420, the superheat of the refrigerant and the evaporation effect of the evaporator 700 can be effectively controlled, thereby improving the efficiency and performance of the entire refrigeration equipment.

[0117] Alternatively, a throttle valve may be installed on the fourth refrigerant line 340 outside the economizer 200.

[0118] By configuring the first orifice plate 410 and / or the second orifice plate 420 as double-layer orifice plates, the flow and pressure changes of the refrigerant can be controlled more precisely, while reducing vibration and noise generated during the throttling process. The double-layer orifice plate design also effectively extends the service life of the first orifice plate 410 and / or the second orifice plate 420, avoiding orifice wear or blockage problems caused by long-term use, thereby improving the stability and reliability of the system.

[0119] Alternatively, the first orifice plate 410 and / or the second orifice plate 420 may be single-layer orifice plates.

[0120] In an optional embodiment of the above-mentioned two-stage compression system, the third refrigerant line 330 further has a first outer extension section 332, on which a first regulating valve 510 is provided; and / or, the fourth refrigerant line 340 further has a second outer extension section 342, on which a second regulating valve 520 is provided.

[0121] By setting the first regulating valve 510, the refrigerant flow rate in the third refrigerant pipeline 330 can be controlled to ensure that the amount of liquid refrigerant in the liquid chamber is relatively sufficient.

[0122] By using the second regulating valve 520 to control the refrigerant flow in the fourth refrigerant line 340, the flow can be coordinated with the first regulating valve 510 to further maintain the amount of refrigerant in the liquid chamber and prevent cross-contamination.

[0123] It should be noted that "gas leakage" here refers to the following: if the refrigerant level in the housing 210 of the economizer 200 is not sufficiently high, and the openings of the first regulating valve 510 and the second regulating valve 520 are relatively large, when the load on the two-stage compression system is low, the gaseous refrigerant in the gas chamber 201 may enter the evaporator 700 through the second orifice plate 420 and the fourth refrigerant line 340, or the gaseous refrigerant flowing out of the condenser 600 may enter the evaporator 700 through the second orifice plate 420 and the fourth refrigerant line 340, resulting in decreased energy efficiency. In this case, the gas leakage can be prevented by adjusting the opening of the first regulating valve 510 and / or the second regulating valve 520.

[0124] Specifically, through testing, when the compressor load is at least 60% of the rated load, the economizer 200 can maintain a certain liquid level, thus avoiding the risk of gas leakage. At this time, the first regulating valve 510 and the second regulating valve 520 remain fully open, i.e., adjusted to their maximum opening. When the compressor load is between 30% and 60% of the rated load, the openings of the first regulating valve 510 and the second regulating valve 520 are maintained at half of their respective maximum openings to avoid the risk of gas leakage. In this design, since the first orifice plate 410 and the second orifice plate 420 cannot adjust the flow rate, gas leakage from the economizer is prevented by adjusting the openings of the first regulating valve 510 and the second regulating valve 520.

[0125] Optionally, the first regulating valve 510 is an electric butterfly valve or an electric ball valve.

[0126] Optionally, the second regulating valve 520 is an electric butterfly valve or an electric ball valve.

[0127] Alternatively, when the compressor is operating at a fixed frequency or variable frequency and under high load, the first regulating valve 510 and / or the second regulating valve 520 are not provided; or, the first regulating valve 510 and the second regulating valve 520 are kept fully open, that is, the opening degree is adjusted to the maximum opening degree.

[0128] Secondly, this application provides a refrigeration device, including the two-stage compression system as described above.

[0129] It should be noted that the above preferred embodiments are merely illustrative of the principles of this application and are not intended to limit the scope of protection of this application. Without departing from the principles of this application, those skilled in the art can adjust the above settings to make this application applicable to more specific application scenarios.

[0130] Those skilled in the art will understand that although some embodiments herein include certain features included in the embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments in the claims of this application can be used in any combination.

[0131] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A two-stage compression system, characterized in that, include: The compressor (100) has a first compression section (110) and a second compression section (120). An economizer (200), located near the compressor (100), includes a housing (210) with a cavity and a separation device disposed within the cavity. The separation device divides the cavity into an upper and lower distributed gas cavity (201) and a liquid cavity (202). The separation device is configured to allow gaseous refrigerant to pass through and to block and collect liquid droplets in the gaseous refrigerant. The housing (210) has a gas inlet and a gas outlet corresponding to the gas cavity (201), and a liquid inlet and a liquid outlet corresponding to the liquid cavity (202). The gas and liquid two-phase refrigerant enters the housing (210) through the liquid inlet. The first refrigerant pipeline (310) is fixedly connected between the outlet of the first compression unit (110) and the gas inlet; The second refrigerant line (320) is fixedly connected between the gas outlet and the air inlet of the second compression unit (120).

2. The two-stage compression system according to claim 1, characterized in that, The separation device is configured as a wire mesh separation layer (220), which includes at least a first layer group (221) and a second layer group (222) arranged from top to bottom. The first layer group (221) includes one or more layers of first wire mesh, and the second layer group (222) includes one or more layers of second wire mesh; The mesh size of the first wire mesh is larger than that of the second wire mesh.

3. The two-stage compression system according to claim 2, characterized in that, The wire mesh separation layer (220) is constructed as a wavy wire mesh.

4. The two-stage compression system according to claim 3, characterized in that, The distance between adjacent crests and troughs of the corrugated wire mesh is 10 mm; and / or The distance between adjacent crests and troughs of the wavy wire mesh is 13 mm.

5. The two-stage compression system according to claim 2, characterized in that, The mesh density of the mesh separation layer (220) is 180 kg / m to 220 kg / m.

6. The two-stage compression system according to any one of claims 1 to 5, characterized in that, The second refrigerant line (320) has an extension section (321) that extends into the gas chamber (201), and the inlet end of the extension section (321) is provided with a gas-liquid separator.

7. The two-stage compression system according to claim 6, characterized in that, Also includes: The third refrigerant line (330) is connected to the liquid inlet; The fourth refrigerant line (340) is connected to the liquid outlet.

8. The two-stage compression system according to claim 7, characterized in that, The third refrigerant line (330) has a first bend (331) extending into the liquid chamber (202), and the interior of the first bend (331) is provided with a first throttling orifice plate (410); and / or The fourth refrigerant pipe (340) has a second bend (341) extending into the liquid chamber (202), and the interior of the second bend (341) is provided with a second throttling orifice plate (420). The first orifice plate (410) and / or the second orifice plate (420) are double-layer orifice plates.

9. The two-stage compression system according to claim 7, characterized in that, The third refrigerant line (330) also has a first external extension section (332), on which a first regulating valve (510) is provided; and / or The fourth refrigerant pipeline (340) also has a second external extension section (342), on which a second regulating valve (520) is provided.

10. A refrigeration device, characterized in that, Includes the two-stage compression system as described in any one of claims 1 to 9.

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