Fluid medium circulation system, compressor and fluid machine

Abstract

The invention relates to a fluid medium circulation system, a compressor and a fluid machine. The fluid medium circulating system comprises a first pipeline, a coaxial pump and a second pipeline. The coaxial pump is installed on the rotating shaft to be driven, the first pipeline is connected to an input port of the coaxial pump so as to receive and transmit the fluid medium leaked from the sealing structure, and the second pipeline is connected to an output port of the coaxial pump so as to circulate the leaked fluid medium back into the fluid storage part. Thus, according to the fluid medium circulation system, the compressor and the fluid machine, fluid medium leakage and / or pollution can be prevented, and the running cost loss of a customer is reduced by recycling the fluid medium.

Description

Technical Field

[0001] The present disclosure relates to the field of fluid machinery, and more specifically to a fluid medium circulation system, a compressor and a fluid machinery. Background Art

[0002] As is known, a mechanical seal is a device that is perpendicular to the end face of a rotating shaft and keeps fit and slides relatively to prevent fluid leakage under the action of the elastic force or other forces of the fluid pressure and elastic force compensation mechanism and with the cooperation of an auxiliary seal. Such mechanical seals are widely used in the field of fluid machinery. Specifically, a fluid machinery may include a compressor. The fluid medium used for the compressor may be, for example, lubricating oil. Since there is a certain pressure difference between the inside of the compressor and the external environment, even if the mechanical seal is used, there will still be a certain leakage of the fluid medium in the compressor. For mechanical seals with different shaft diameters, the national standard has certain requirements for the leakage rate. For example, when the shaft diameter of the mechanical seal is 65mm, the leakage rate of the mechanical seal must be less than or equal to 3ml / h. As the machine continues to run for a long time, the leakage of the fluid medium will cause insufficient fluid medium in the compressor. At the same time, the leakage of the fluid medium directly discharged into the environment will also cause certain pollution to the environment.

[0003] Therefore, technical improvements are needed to solve at least one of the problems of fluid medium leakage and contamination. Summary of the invention

[0004] The present disclosure aims to provide a fluid medium circulation system to solve the above technical problems. Moreover, the fluid medium circulation system is not limited to being used in a compressor, but can be applied to any machine with a rotating shaft to circulate leaked fluid medium.

[0005] In one aspect, the present disclosure provides a fluid medium circulation system. The fluid medium circulation system comprises a first pipeline, a coaxial pump and a second pipeline. The coaxial pump is installed on a rotating shaft and driven. The first pipeline is connected to the input port of the coaxial pump to receive and transmit the fluid medium leaked from the sealing structure. The second pipeline is connected to the output port of the coaxial pump to circulate the leaked fluid medium back into the fluid storage part.

[0006] In this way, the fluid medium circulation system according to the present disclosure can realize the recycling of leaked fluid medium by setting the first pipeline, the coaxial pump and the second pipeline, thereby avoiding the leakage of the fluid medium directly discharged into the environment to cause pollution problems, and also reducing the operating cost loss of customers by recycling the leaked oil. In addition, the coaxial pump is directly installed on the rotating shaft, so there is no need to add a pump driver.

[0007] In one or more embodiments, the sealing structure includes a mechanical sealing structure mounted on the rotating shaft coaxially with the coaxial pump.

[0008] In this way, the mechanical seal structure provides a good sealing effect for the rotating shaft.

[0009] In one or more embodiments, the mechanical seal structure has a mechanical seal cover plate. The first pipeline is connected to a drain port disposed at a lower portion of the mechanical seal cover plate.

[0010] In this way, the drain port is convenient for discharging the leaked fluid medium smoothly and timely.

[0011] In one or more embodiments, the fluid medium circulation system further includes a leakage-proof structure disposed in the mechanical sealing cover plate.

[0012] In this way, the provision of the leakage-proof structure prevents the leaked fluid medium from further leaking from the distal end of the mechanical seal cover plate.

[0013] In one or more embodiments, the anti-leakage structure includes a reservoir and / or a sealing component to prevent the leaked fluid medium from further leaking from the distal end of the mechanical seal cover plate.

[0014] In this way, the provision of the storage tank and / or the sealing component can further prevent the leaked lubricating oil from leaking from the distal end of the mechanical seal cover plate, which can further reduce or eliminate the leakage rate of the mechanical seal structure.

[0015] In one or more embodiments, the reservoir is at least partially located below the rotating shaft and is configured to block a passage to a distal end of the mechanical seal cover plate and to collect and store fluid media leaked from the mechanical seal structure.

[0016] In this way, the provision of the reservoir can further prevent the fluid medium from leaking from the distal end of the mechanical seal cover plate.

[0017] In one or more embodiments, the drain port is disposed at the bottom of the storage tank.

[0018] In this way, the leakage port provided in this way ensures that the fluid medium leaking from the mechanical seal structure can be discharged from the storage tank through the leakage port in time.

[0019] In one or more embodiments, the sealing component is disposed within a distal end of the mechanical seal cover plate adjacent to the reservoir and around the rotation axis.

[0020] In this way, provision of the sealing component can further prevent the fluid medium from leaking from the distal end of the mechanical seal cover plate into the environment.

[0021] In one or more embodiments, the storage volume of the reservoir is between 36 ml and 72 ml.

[0022] In this way, even if leakage occurs when the screw compressor is not running, the storage volume can ensure that the fluid medium stored in the storage tank will not overflow from the distal end of the mechanical seal cover plate.

[0023] In one or more embodiments, the storage tank has a configuration with a circular, rectangular, semicircular or polygonal cross-section.

[0024] Thus, the storage tank having such a structure can be easily processed.

[0025] In one or more embodiments, a reservoir having a semicircular configuration is disposed around the rotation axis and on the underside of the rotation axis.

[0026] In this way, the storage tank constructed in this way can also reduce the processing cost of the mechanical seal cover plate and ensure the strength of the mechanical seal cover plate.

[0027] In one or more embodiments, the coaxial pump includes an internal gear fixed on the rotating shaft to rotate synchronously with the rotating shaft.

[0028] In this way, the rotating shaft drives the coaxial pump synchronously when it runs, so there is no need to add a pump driver. The rotation of the internal gear is used to pump the leaking fluid medium.

[0029] In one or more embodiments, the coaxial pump includes a pump housing fixed to a casing of a machine, the internal gear is accommodated in the pump housing, and the input port and the output port are arranged on the pump housing.

[0030] In this way, the coaxial pump thus constructed provides a pumping action so as to circulate the fluid medium leaking from the mechanical seal structure back into the oil reservoir.

[0031] In one or more embodiments, the mechanical seal structure further includes a mechanical seal static ring, a mechanical seal dynamic ring, a static ring auxiliary seal, a dynamic ring auxiliary seal and an elastic force compensation mechanism to cooperatively provide a sealing effect.

[0032] In this way, the mechanical seal structure constructed in this way can provide a good sealing effect for the rotating shaft to prevent leakage of the fluid medium.

[0033] In another aspect, the present disclosure provides a compressor comprising the fluid medium circulation system according to the present disclosure.

[0034] In this way, the compressor according to the present disclosure can prevent leakage and / or contamination of the fluid medium by using the fluid medium circulation system according to the present disclosure, and reduce the operating cost loss of the customer by recycling the fluid medium.

[0035] In one or more embodiments, the compressor includes a compressor body, a rotating shaft and a casing. The rotating shaft extends from the compressor body and is at least partially encapsulated in the casing. A mechanical seal structure is arranged around the rotating shaft at the suction end of the compressor between the rotating shaft and the casing. The fluid medium circulation system is configured to circulate the fluid medium leaking from the mechanical seal structure.

[0036] In this way, the mechanical seal structure provides a good sealing effect for the rotating shaft of the compressor, and the fluid medium circulation system further recycles the fluid medium leaked from the mechanical seal structure to prevent environmental pollution and reduce operating cost losses.

[0037] In one or more embodiments, the compressor further comprises a heat exchanger disposed adjacent to the compressor body and a main oil supply pipeline for supplying high-temperature refrigeration oil, the second pipeline of the fluid medium circulation system conveys the low-temperature fluid medium leaking from the mechanical seal structure, the main oil supply pipeline and the second pipeline extend through the heat exchanger before being connected to the compressor body, so that the high-temperature refrigeration oil and the low-temperature fluid medium are heat exchanged.

[0038] In this way, the leaked low-temperature fluid medium is reused at the heat exchanger to exchange heat with the main oil in the main oil supply pipeline to reduce the temperature of the main oil supply. This solves the problem of compressor oil cooling to a certain extent. After the cooled main oil enters the compressor, it can lubricate and cool the bearings, screw shafts, etc., giving full play to the oil cooling effect.

[0039] In one or more embodiments, the flow storage part is a closed tooth groove of a screw rotor of the compressor, and the second pipeline is connected to a tooth groove inlet leading to the closed tooth groove of the screw rotor.

[0040] In this way, the leaked fluid medium can be circulated back to the closed tooth grooves of the screw rotor in the compressor body for recycling.

[0041] In yet another aspect, the present disclosure provides a fluid machine including the compressor according to the present disclosure.

[0042] In this way, the fluid machinery according to the present disclosure using the fluid medium circulation system according to the present disclosure can prevent leakage and / or contamination of the fluid medium, and reduce the operating cost loss of the customer by recycling the fluid medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present disclosure will be more easily understood by the following detailed description in conjunction with the accompanying drawings, in which the same reference numerals represent the same elements. The accompanying drawings are schematic and non-restrictive. The elements in the accompanying drawings are not necessarily represented to scale, for example, the elements may be enlarged for the purpose of illustration, or may be reduced in proportion to keep the drawings clear and easy to understand.

[0044] In the attached picture:

[0045] Figure 1 A cross-sectional view of a compressor using a mechanical seal structure in the prior art is schematically shown.

[0046] Figure 2 A cross-sectional view of a compressor provided with a fluid medium circulation system according to the present disclosure is schematically shown.

[0047] Figure 3 Schematically shows Figure 2 An enlarged view of the fluid medium circulation system is shown.

[0048] Description of reference numerals:

[0049] Screw compressor 1; rotor shaft 2; drain port 3; casing 4; coaxial pump 5; compressor body 6; heat exchanger 7; main oil supply pipeline 8; mechanical seal structure 10; mechanical seal static ring 12; mechanical seal dynamic ring 14; static ring auxiliary seal 16; dynamic ring auxiliary seal 17; elastic compensation mechanism 18; mechanical seal cover plate 19; storage tank 31; sealing component 32; first pipeline 33; second pipeline 34; pump casing 51; internal gear 52; input port 53; output port 54; tooth groove inlet 62; main oil supply port 64. DETAILED DESCRIPTION

[0050] The present disclosure will be described below with reference to the accompanying drawings, wherein the accompanying drawings show several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in a variety of different ways and is not limited to the embodiments described below. The embodiments described below are intended to make the disclosure of the present disclosure more complete and fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should be understood that in all the drawings, the same reference numerals represent the same elements.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art in the art of the present disclosure. For the sake of brevity and / or clarity, well-known functions or structures may not be described in detail. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0052] The term "comprise" and its derivatives in the specification and claims of the present disclosure are intended to be open terms, which specify the presence of claimed features, elements, components, groups, integers and / or steps, but do not exclude the presence of other undescribed features, elements, components, groups, integers and / or steps. This concept also applies to words with similar meanings, such as the terms "have", "include" and their derivatives.

[0053] The terms "part," "element," "member" and the like can have the dual meaning of a single part or a plurality of parts.

[0054] In the description of the embodiments of the present disclosure, the terms "first", "second", etc. are only used to distinguish different objects, and should not be understood as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features. In addition, the term "first component" itself does not imply the existence of a "second component", and the term "second component" itself does not imply the existence of a "first component".

[0055] In the description of the embodiments of the present disclosure, “plurality” means more than two, unless explicitly defined otherwise.

[0056] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0057] In the description of the embodiments of the present disclosure, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent the following three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0058] In the description of the embodiments of the present disclosure, the terms "distal", "proximal", "up", "down", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present disclosure and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be configured and operated in a specific direction. Therefore, they should not be understood as limiting the embodiments of the present disclosure.

[0059] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, the terms "installation", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0060] The machine as described herein can be any equipment with a rotating shaft and a shaft sealing structure. The fluid machinery as described herein can include a compressor, especially a screw compressor. More specifically, the screw compressor can be an open screw compressor. Lubricating oil will be used as an example of a fluid medium for a compressor below.

[0061] In this article, the orientation of the rotor shaft of the screw compressor is used as an example to define "proximal side" and "distal side". Specifically, one side of the rotating shaft located in the compressor body is called "proximal side", and the other side is called "distal side".

[0062] With the continuous updating of screw compressor technology, it has been widely used in the fields of air conditioning, refrigeration, freezing and chemical industry. A shaft sealing structure can be set in the casing of the screw compressor and at the end of the rotor shaft to prevent the high-pressure refrigerant in the compressor from leaking to the outside. A separate shaft sealing structure cannot achieve the sealing function and needs to be used in conjunction with lubricating oil, so oil is supplied to the shaft sealing structure for lubrication. Existing compressors are provided with a shaft seal lubrication structure on the rotor shaft of the compressor. In order to prevent the lubricating oil from losing too quickly, a lip seal (for example, an oil retaining ring) that can store lubricating oil is also provided on the shaft seal lubrication structure, and the lip seal is installed on the housing near the shaft seal structure. Due to the pressure difference in the compressor, the lubricating oil will leak from the shaft seal structure and the lip seal, resulting in the problem of no lubrication of the compressor rotating shaft after long-term operation or long-term shutdown. In any case, the problem of lubricating oil leakage still exists, and a more effective sealing structure needs to be provided.

[0063] The prior art has disclosed a shaft seal oil supply structure for a screw compressor that is effective in long-term shutdown, and is particularly applicable to open compressors with long-term (more than half a year) shutdown conditions. The screw compressor includes a casing, a rotor shaft installed inside the casing, and a main oil supply pipeline provided on the casing. A shaft seal lubrication structure is provided at the end of the rotor shaft, and the shaft seal lubrication structure has an oil outlet for the lubricating oil circuit. The oil outlet is arranged toward the low-pressure area inside the casing, and the oil outlet end of the lubricating oil circuit is connected to the oil outlet. The shaft seal oil supply structure is configured such that: the oil storage area is located above the shaft seal lubrication structure and lubricating medium is always stored in the oil storage area. The main oil supply pipeline, the oil storage area, the connecting oil circuit, the lubricating oil circuit, and the oil outlet are connected in series. When the screw compressor needs to be started after being shut down, the solenoid valve is opened to allow the lubricating medium stored in the oil storage area to flow from the oil storage area to the lubricating oil circuit through the connecting oil circuit. However, the shaft seal oil supply structure has a circulating flow path inside, which not only makes the internal structure complicated, but also requires an oil storage area that always stores lubricating medium above the shaft seal lubrication structure, thereby making the structure extremely complicated.

[0064] Figure 1The schematic diagram shows a cross-sectional view of a compressor using a mechanical seal structure in the prior art. The mechanical seal structure 10 can provide more effective sealing compared to the previous seal structure. As is known, the working principle of the mechanical seal structure 10 is: relying on the elastic element to provide elastic force, overcome the friction between the auxiliary seal ring of the compensation dynamic ring and the rotating shaft, so that the compensation ring fits tightly on the end face of the non-compensation ring, forming an initial closing force on the sealing end face. When the machine is filled with pressure medium and starts working, the sealing end face can generate a closing force, so that the sealing end face reaches a reasonable specific pressure, thereby achieving fluid sealing.

[0065] The applicant makes full use of the structure and principle of the known mechanical seal structure (reference Figure 1 ) has made technical improvements to the seal of screw compressors. Figure 1 As shown, the compressor may be a screw compressor 1. As an example of a rotating shaft of a machine, a rotor shaft 2 of the screw compressor 1 is rotatably mounted in a casing 4 (e.g., a pressure casing) of the compressor. A mechanical seal structure 10 may be disposed around the rotor shaft 2 and between the rotor shaft 2 and the casing 4 to prevent lubricating oil leakage.

[0066] exist Figure 1 In the example shown, the mechanical seal structure 10 may mainly include components such as a mechanical seal static ring 12 , a mechanical seal dynamic ring 14 , a static ring auxiliary seal 16 , a dynamic ring auxiliary seal 17 , an elastic force compensation mechanism 18 and a mechanical seal cover plate 19 .

[0067] The first end of the mechanical seal dynamic ring 14 is arranged to abut against the mechanical seal static ring 12, and the second end of the mechanical seal dynamic ring 14 opposite to the first end is abutted by the elastic compensation mechanism 18. The mechanical seal static ring 12 and the mechanical seal dynamic ring 14 are kept in close contact to form a sealing end face, thereby preventing leakage of the fluid medium. The mechanical seal static ring 12 and the mechanical seal dynamic ring 14 need to have good wear resistance. The mechanical seal dynamic ring 14 can move axially to automatically compensate for the wear of the sealing end face, so that it fits well with the mechanical seal static ring 12 to prevent leakage of lubricating oil. The mechanical seal static ring 12 can have a certain floatability to play a buffering role.

[0068] The stationary ring auxiliary seal 16 is arranged between the mechanical seal stationary ring 12 and the mechanical seal cover plate 19. Specifically, the stationary ring auxiliary seal 16 is arranged around the rotor shaft 2 adjacent to the distal end surface of the mechanical seal stationary ring 12 and the proximal end surface of the mechanical seal cover plate 19, in order to ensure the sealing between the mechanical seal stationary ring 12 and the mechanical seal cover plate 19. Thus, the lubricating oil is prevented from leaking through the mechanical seal cover plate 19.

[0069] The auxiliary dynamic ring seal 17 is arranged to surround the rotor shaft 2 at the second end of the mechanical seal dynamic ring 14 and is arranged in the inner surface of the mechanical seal dynamic ring 14. The auxiliary dynamic ring seal 17 is intended to ensure the sealing between the mechanical seal dynamic ring 14 and the rotor shaft 2.

[0070] The stationary ring auxiliary seal 16 and the dynamic ring auxiliary seal 17 can be O-rings, V-rings, wedge rings and other special-shaped sealing rings, which mainly play the role of sealing the mechanical seal stationary ring 12 and the mechanical seal dynamic ring 14, and also have floating and buffering effects. Figure 1 In the example shown, the stationary ring auxiliary seal 16 and the dynamic ring auxiliary seal 17 are formed by O-rings.

[0071] One end of the elastic compensation mechanism 18 is disposed against the housing 4, and the other end is disposed against the second end of the mechanical seal dynamic ring 14. The elastic compensation mechanism 18 mainly plays the role of compensation, pre-tightening and buffering, and also generates a reasonable spring specific pressure on the sealing end surface. The elastic compensation mechanism 18 always maintains elasticity to overcome the friction between the dynamic ring auxiliary seal and the transmission part to start the compensation function. The elastic compensation mechanism 18 can be a spring, a corrugated plate, a serpentine sleeve, etc. Figure 1 In the example shown, the elastic force compensation mechanism 18 is a dynamic ring preload spring. The transmission member (not shown) is used to transmit the torque of the rotor shaft 2 to the mechanical seal dynamic ring 14. The transmission member may include a transmission pin, a transmission ring, a transmission seat, a transmission sleeve, a transmission key, a transmission lug or a tooth-type connector.

[0072] exist Figure 1 In the example shown, Figure 1 The left side of the figure shows the suction side of the screw compressor and the right side shows the atmosphere. Figure 1 The mechanical seal structure 10 shown can provide a good sealing effect for the screw compressor to prevent lubricating oil leakage. However, under the effect of the pressure difference between the suction side and the atmospheric environment, a small amount of lubricating oil inside the screw compressor will still leak through the mechanical seal structure 10 and be directly discharged into the environment through the drain port 3.

[0073] As mentioned above, since the mechanical seal structure 10 has a certain leakage rate and the leaked lubricating oil is directly discharged into the environment, as the screw compressor continues to operate for a long time, the leakage will cause insufficient lubricating oil in the compressor and cause certain pollution to the environment. In other words, since the lubricating oil leaked from the mechanical seal structure 10 is directly discharged into the environment, there is still a problem of lubricating oil leakage and pollution.

[0074] Based on the state of the prior art, the following will take a screw compressor as an example to illustrate how the fluid medium circulation system according to the present disclosure prevents leakage and / or contamination of the fluid medium (taking lubricating oil as an example), and reduces the customer's operating cost losses by recycling the leaked oil.

[0075] The overall inventive concept of the present disclosure is that, under the sealing level of the existing shaft sealing structure, the fluid medium leaked from the shaft sealing structure is circulated back to the fluid storage part of the machine by utilizing a fluid medium circulation system including a first pipeline, a coaxial pump and a second pipeline. Specifically, the fluid medium circulation system according to the present disclosure may include a first pipeline, a coaxial pump and a second pipeline. The coaxial pump is installed on the rotating shaft of the machine to be driven. The first pipeline and the second pipeline can be connected to the input port and the output port of the coaxial pump respectively to circulate the fluid medium leaked from the shaft sealing structure of the machine back to the fluid storage part of the machine. In this way, the fluid medium circulation system according to the present disclosure avoids the leakage of the fluid medium directly discharged into the environment to cause pollution problems, and also reduces the operating cost loss by recycling the leaked oil. Moreover, the coaxial pump is directly installed on the rotating shaft and driven by the rotating shaft, so there is no need to add a pump driver. The machine can be any machine with a specific rotating shaft, and this article takes a screw compressor as an example for explanation. The shaft sealing structure can be any sealing structure, such as the above-mentioned mechanical sealing structure, a common labyrinth seal or other seals. This article takes the above-mentioned mechanical sealing structure as an example for further improvement.

[0076] To this end, on the basis of the mature mechanical seal structure of the existing screw compressor, the fluid medium circulation system according to the present disclosure adds a storage tank and a sealing component to prevent the leaked lubricating oil from further leaking from the distal end of the mechanical seal cover plate. This can reduce or eliminate the leakage rate of the mechanical seal structure. A coaxial pump and a first pipeline and a second pipeline connected to the input end and the output end of the coaxial pump are added to the rotor shaft of the screw compressor, and the low-temperature lubricating oil leaked into the storage tank is drained into the flow storage part of the compressor body (such as the closed tooth groove of the screw rotor) for recycling. In this way, the operating cost loss is reduced by recycling the leaked oil. At the same time, before entering the flow storage part of the compressor body, the recovered leaked low-temperature lubricating oil and the main supply oil are used for heat exchange in a heat exchanger to reduce the temperature of the main supply oil. Therefore, the secondary utilization of the leaked low-temperature fluid medium can effectively solve the oil cooling problem of the compressor.

[0077] Figure 2 A cross-sectional view of a compressor provided with a fluid medium circulation system according to the present disclosure is schematically shown. Figure 3 Schematically shows Figure 2 The enlarged view of the fluid medium circulation system shown is to more clearly show the components of the fluid medium circulation system. Among them, the reference numeral 5 overall identifies the coaxial pump, and the reference numeral 10 overall identifies the mechanical seal structure.

[0078] exist Figure 2In the example shown, the compressor may be a screw compressor 1. More specifically, the compressor may be an open screw compressor. The screw compressor 1 may include a compressor body 6, a rotor shaft 2, and a casing 4. The rotor shaft 2 extends from the compressor body 6 and is at least partially encapsulated in the casing 4. The rotor shaft 2 is rotatably mounted in the casing 4. A mechanical seal structure 10 may be disposed around the rotor shaft 2 at the suction end of the compressor between the rotor shaft 2 and the casing 4 to prevent leakage of the fluid medium.

[0079] and Figure 1 The structure and function of the mechanical seal structure 10 shown are the same. Figure 2 The mechanical seal structure 10 shown may also mainly include a mechanical seal stationary ring 12, a mechanical seal dynamic ring 14, a stationary ring auxiliary seal 16, a dynamic ring auxiliary seal 17, an elastic force compensation mechanism 18 and a mechanical seal cover plate 19, so as to cooperatively provide a good sealing effect. For the sake of simplicity, each component may be represented by the same reference numeral, and its structure and function will not be described in detail.

[0080] In such Figure 1 In the compressor shown, even if a mechanical seal structure 10 with a strong sealing effect is adopted, there are still leakage and contamination problems to a certain extent.

[0081] To resolve fluid media leakage and / or contamination issues, refer to Figure 2 and Figure 3 According to the present disclosure, the fluid medium circulation system may include at least a first pipeline 33, a coaxial pump 5, and a second pipeline 34. The coaxial pump 5 is mounted on the rotor shaft 2 (i.e., a specific example of a rotating shaft) of the screw compressor 1, thereby eliminating the need to add a pump driver. Specifically, the coaxial pump 5 and the mechanical seal structure 10 are coaxially mounted on the rotor shaft 2 of the screw compressor 1. The mechanical seal structure 10 includes a mechanical seal cover plate 19. The drain port 3 may be provided at the lower portion of the mechanical seal cover plate 19 to facilitate smoother and timely discharge of leaked fluid medium (e.g., lubricating oil).

[0082] refer to Figure 2 and Figure 3 , the first pipeline 33 is connected between the discharge port 3 of the mechanical seal structure 10 and the input port 53 of the coaxial pump 5. The second pipeline 34 is connected between the output port 54 of the coaxial pump 5 and the compressor body 6 to circulate the fluid medium leaking from the mechanical seal structure 10 back to the reservoir of the compressor body 6. Specifically, the reservoir of the screw compressor 1 can be a closed tooth groove (not shown) of the screw rotor of the screw compressor 1, and the tooth groove inlet 62 (schematically shown) leads to the closed tooth groove of the screw rotor. The second pipeline 34 is connected between the output port 54 of the coaxial pump 5 and the tooth groove inlet 62. The second pipeline 34 passes through the casing 4 of the compressor (for example, it can be an orifice in the casing, only schematically shown) and is connected to the tooth groove inlet 62.

[0083] In this way, the fluid medium circulation system according to the present invention can realize the recycling of leaked fluid medium by simply setting up a first pipeline, a coaxial pump and a second pipeline, avoiding the leakage of fluid medium directly discharged into the environment to cause pollution problems, and also reducing customers' operating cost losses by recycling leaked oil.

[0084] During operation, under the pumping action of the coaxial pump 5, the fluid medium discharged from the drain port 3 of the mechanical seal structure 10 is transmitted to the input port 53 of the coaxial pump 5 via the first pipeline 33, and is transmitted to the tooth groove inlet 62 via the second pipeline 34 at the output port 54 of the coaxial pump 5 and flows to the screw rotor closed tooth groove 6 of the screw compressor 1. In this way, the fluid medium leaked from the mechanical seal structure 10 returns to the compressor body via the drain port 3, the first pipeline 33, the coaxial pump 5 and the second pipeline 34, thereby realizing the recycling of the fluid medium, thereby avoiding environmental pollution and reducing the loss of operating costs.

[0085] In addition to the mechanical seal structure 10 preventing the lubricating oil from leaking, the fluid medium circulation system according to the present disclosure can also prevent the leaked lubricating oil from further leaking from the distal end of the mechanical seal cover plate by means of the anti-leakage structure disposed in the mechanical seal cover plate, thereby further reducing or eliminating the leakage rate of the mechanical seal structure.

[0086] Herein, the distal end of the mechanical seal cover plate 19 refers to the end of the mechanical seal cover plate 19 that faces away from the compressor body 6. Such a leakage prevention structure may include a reservoir and / or a sealing component disposed in the mechanical seal cover plate 19.

[0087] In one example, the anti-leakage structure may include a storage tank 31 disposed in the mechanical seal cover plate 19. The storage tank 31 is at least partially located below the rotor shaft 2 and is configured to block the passage to the distal end of the mechanical seal cover plate 19 and to collect and store the fluid medium leaked from the mechanical seal structure. Since at least a portion of the cavity of the storage tank 31 is located below the rotor shaft 2, the lubricating oil leaked from the mechanical seal structure 10 is drained and collected into the storage tank 31 due to gravity. Moreover, the storage tank 31 also blocks the passage for the lubricating oil to flow directly to the distal end of the mechanical seal cover plate 19. Thus, the provision of the storage tank can further prevent the leaked lubricating oil from leaking from the distal end of the mechanical seal cover plate, thereby further reducing or eliminating the leakage rate of the mechanical seal structure.

[0088] In one example, the drain port 3 may be disposed at the bottom of the reservoir 31, thereby ensuring that the lubricating oil leaking from the mechanical seal structure 10 can be promptly discharged from the reservoir 31 via the drain port 3. This prevents excessive lubricating oil from being stored and overflowing from the distal end of the mechanical seal cover plate.

[0089] In another example, in order to prevent lubricating oil from leaking from the distal end of the mechanical seal cover plate 19 to the environment, the anti-leakage structure may include a sealing component 32, which is arranged in the distal end of the mechanical seal cover plate 19 around the rotor shaft 2. The sealing component 32 can have any feasible structure. Specifically, the sealing component 32 can be a lip seal with a conventional structure.

[0090] In yet another example, the anti-leakage structure may include a tank 31 and a sealing member 32. The sealing member 32 is disposed adjacent to the tank 31 and in the distal end of the mechanical seal cover plate 19 around the rotor shaft 2. Specifically, the sealing member 32 is disposed adjacent to the tank 31 and on the right side of the tank 31.

[0091] In addition, the storage tank 31 may have a storage volume of 36 ml ≤ V ≤ 72 ml (milliliters). The storage volume is mainly a parameter value set based on the oil leakage of the screw compressor in the industry after adopting the mechanical seal structure and adding some margin on it. According to the specific application, a more appropriate storage volume can be set. In this way, even if leakage occurs when the screw compressor is not running, the storage volume can ensure that the lubricating oil stored in the storage tank will not overflow from the distal end of the mechanical seal cover plate.

[0092] The reservoir 31 may have a structure that is easy to process, such as a structure with a circular, rectangular, semicircular or polygonal cross section, to collect and store the lubricating oil leaked from the mechanical seal structure 10. In this way, the reservoir 31 may provide a receiving space and block the passage to the distal end of the mechanical seal cover plate to prevent the lubricating oil from leaking from the distal end of the mechanical seal cover plate 19.

[0093] exist Figure 2 In the example shown, the reservoir 31 may have a circular configuration to facilitate machining.

[0094] In an example not shown, the storage tank 31 may have a semicircular configuration provided at the lower side of the rotor shaft 2. In this way, the processing cost of the mechanical seal cover plate can be reduced and the strength of the mechanical seal cover plate can be ensured.

[0095] like Figure 2 and Figure 3 As shown, the coaxial pump 5 is arranged in the local space on the right side of the mechanical seal cover plate 19. The coaxial pump 5 can be arranged adjacent to the mechanical seal cover plate 19 to provide a compact layout. The coaxial pump 5 can be arranged spaced apart from the mechanical seal cover plate 19. The coaxial pump 5 can be a coaxial oil pump mounted on the rotor shaft 2, so that there is no need to add a pump driver.

[0096] The coaxial pump 5 may include a pump housing 51 fixed to the casing 4 and an internal gear 52 accommodated in the pump housing 51. The internal gear 52 of the coaxial pump 5 is fixed to the rotor shaft 2, and a key is installed between the two. In this way, the rotor shaft 2 drives the internal gear 52 through the key so that the two operate synchronously. In other words, when the rotor shaft 2 of the screw compressor 1 operates, it drives the coaxial pump 5 to operate synchronously, so there is no need to add a pump driver.

[0097] The cavity formed between the pump housing 51 and the internal gear 52 is used to receive the lubricating oil transmitted from the first pipeline 33. The pump housing 51 is provided with an input port 53 and an output port 54 of the coaxial pump for receiving the lubricating oil from the first pipeline 33 and pumping the input lubricating oil to the second pipeline 34. The rotor shaft 2 drives the internal gear 52 to rotate through the key, thereby pushing the lubricating oil contained in the cavity between the pump housing 51 and the internal gear 52 to be delivered to the second pipeline 34 through the output port 54. In this way, the coaxial pump 5 provides a pumping action so as to pump and circulate the lubricating oil leaking from the mechanical seal structure 10 back into the oil storage part of the screw compressor 1.

[0098] The pump housing 51 of the coaxial pump 5 is fixed to the housing 4 via a connection structure. For example, the coaxial pump 5 can be fixed to the housing 4 via 2 to 3 protrusions (not shown) provided on the pump housing 51. The number of protrusions may be greater.

[0099] The present disclosure also relates to a compressor, which further comprises a fluid medium circulation system according to the present disclosure. The compressor comprises a compressor body 6, a rotor shaft 2 and a casing 4. The rotor shaft 2 extends from the compressor body 6 and is at least partially encapsulated in the casing. A mechanical seal structure 10 is arranged around the rotor shaft 2 at the suction end of the compressor between the rotor shaft and the casing. The fluid medium circulation system is configured to circulate the fluid medium leaking from the mechanical seal structure.

[0100] Therefore, the compressor according to the present disclosure can prevent leakage and contamination of the fluid medium by using the fluid medium circulation system according to the present disclosure, and reduce the operating cost loss of the customer by recycling the leaked oil.

[0101] The refrigerant oil of the compressor generally enters the compressor through the main oil supply pipeline for lubrication and cooling. As the compressor continues to operate, the temperature of the refrigerant oil entering the compressor will increase. Therefore, an additional oil cooler is required to cool the refrigerant oil. However, the oil cooler generally needs to introduce low-temperature refrigerant from the system to cool it, which will affect the refrigeration system and reduce the overall efficiency of the system.

[0102] In the compressor, since the low-temperature refrigerant enters from the suction end of the compressor and the high-temperature refrigerant is discharged from the exhaust end of the compressor, the temperature of the suction end is relatively low. In this way, the temperature of the refrigeration oil leaked from the suction end is relatively low, and can be used to cool the refrigeration oil in the main oil circuit, thereby reducing the cooling capacity demand of the oil cooler. Based on the fact that the fluid medium leaked from the suction end of the compressor itself has a relatively low temperature and is suitable for heat exchange with the high-temperature oil in the main oil supply pipeline, the low-temperature fluid medium transmitted from the second pipeline of the fluid medium circulation system according to the present disclosure can be reused through a heat exchanger arranged adjacent to the compressor to cool the high-temperature refrigeration oil transmitted by the main oil supply pipeline.

[0103] The specific concept of the present disclosure is that the screw compressor 1 may include a heat exchanger 7 arranged adjacent to the compressor body 6 and a main oil supply pipeline 8 for supplying high-temperature refrigeration oil. The second pipeline 34 conveys the low-temperature fluid medium leaking from the suction end of the compressor. The main oil supply pipeline 8 and the second pipeline 34 extend through the heat exchanger 7 before being connected to the compressor body 6, so that the high-temperature refrigeration oil and the low-temperature fluid medium perform heat exchange in the heat exchanger 7.

[0104] To this end, the compressor according to the present disclosure may include a heat exchanger 7. The heat exchanger 7 may be a small heat exchanger disposed adjacent to the compressor body 6. The heat exchanger may have a conventional structure and function, which will not be described in detail herein.

[0105] The second pipeline 34 extends through the heat exchanger 7 and the main oil supply pipeline 8 extends through the heat exchanger 7, so that the low-temperature lubricating oil in the second pipeline exchanges heat with the high-temperature refrigeration oil in the main oil supply pipeline 8, thereby cooling the high-temperature refrigeration oil.

[0106] Specifically, the second pipeline 34 extends through the heat exchanger 7 before entering the reservoir (e.g., the screw rotor closed slot) in the compressor body 6 via the slot inlet 62. The main oil supply pipeline 8 extends through the heat exchanger 7 before entering the screw compressor 1 via the main oil supply port 64. The main oil supply pipeline 8 and the second pipeline 34 achieve heat exchange between the fluid medium they transmit at the heat exchanger 7, thereby fully utilizing the low-temperature fluid medium transmitted by the second pipeline. That is, the heat exchanger 7 is located on the upstream side of the slot inlet 62 and the main oil supply port 64.

[0107] In this way, in the heat exchanger 7, the low-temperature lubricating oil leaked in the second pipeline 34 (i.e., reused at the heat exchanger) exchanges heat with the main oil in the main oil supply pipeline 8 to reduce the temperature of the main oil supply. This solves the problem of compressor oil cooling to a certain extent. After the main oil supply after cooling enters the screw compressor 1, it can lubricate and cool the bearings, screw rotating shaft, etc., giving full play to the oil cooling effect.

[0108] In addition, the present disclosure also relates to a fluid machine, which includes the compressor according to the present disclosure.

[0109] Therefore, the fluid machinery according to the present disclosure can prevent leakage and contamination of the fluid medium by using the fluid medium circulation system according to the present disclosure, and reduce the operating cost loss of the customer by recycling the leaked oil.

[0110] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, it should be understood by those of ordinary skill in the art that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present disclosure is not limited to the specific embodiments disclosed herein, but includes all possible technical solutions that fall within the scope of the claims.

Claims

1. A fluid medium circulation system, characterized in that: The fluid medium circulation system includes a first pipeline, a coaxial pump and a second pipeline. The coaxial pump is installed on a rotating shaft and is driven. The first pipeline is connected to the input port of the coaxial pump to receive and transmit the fluid medium leaked from the sealing structure. The second pipeline is connected to the output port of the coaxial pump to circulate the leaked fluid medium back to the fluid storage part.

2. The fluid medium circulation system according to claim 1, characterized in that: The sealing structure comprises a mechanical sealing structure installed on a rotating shaft coaxially with the coaxial pump.

3. The fluid medium circulation system according to claim 2, characterized in that: The mechanical seal structure has a mechanical seal cover plate, and the first pipeline is connected to a drain port provided at a lower portion of the mechanical seal cover plate.

4. The fluid medium circulation system according to claim 3, characterized in that: The fluid medium circulation system also includes an anti-leakage structure arranged in the mechanical sealing cover plate.

5. The fluid medium circulation system according to claim 4, characterized in that: The anti-leakage structure includes a storage tank and / or a sealing component to prevent the leaked fluid medium from further leaking from the distal end of the mechanical seal cover plate.

6. The fluid medium circulation system according to claim 5, characterized in that: The reservoir is at least partially located below the rotating shaft and is configured to block a passage to a distal end of the mechanical seal cover plate and to collect and store fluid media leaked from the mechanical seal structure.

7. The fluid medium circulation system according to claim 6, characterized in that: The drain port is arranged at the bottom of the storage tank.

8. The fluid medium circulation system according to claim 5, characterized in that: The sealing member is disposed adjacent to the reservoir and around the rotation axis within the distal end of the mechanical seal cover plate.

9. The fluid medium circulation system according to claim 6, characterized in that: The storage volume of the reservoir is between 36 ml and 72 ml.

10. The fluid medium circulation system according to claim 6, characterized in that: The storage tank has a circular, rectangular, semicircular or polygonal cross-section.

11. The fluid medium circulation system according to claim 10, characterized in that: A storage tank having a semicircular configuration is disposed around the rotation axis at the lower side of the rotation axis.

12. The fluid medium circulation system according to any one of claims 1 to 11, characterized in that: The coaxial pump includes an internal gear fixed on the rotating shaft to rotate synchronously with the rotating shaft.

13. The fluid medium circulation system according to claim 12, characterized in that: The coaxial pump includes a pump housing fixed to a casing of a machine, the internal gear is accommodated in the pump housing, and the inlet and outlet are arranged on the pump housing.

14. The fluid medium circulation system according to any one of claims 2 to 11, characterized in that: The mechanical seal structure further comprises a mechanical seal static ring, a mechanical seal dynamic ring, a static ring auxiliary seal, a dynamic ring auxiliary seal and an elastic force compensation mechanism to cooperatively provide a sealing effect.

15. A compressor, characterized in that: The compressor comprises a fluid medium circulation system according to any one of claims 1-14.

16. The compressor according to claim 15, characterized in that The compressor includes a compressor body, a rotating shaft and a casing, wherein the rotating shaft extends from the compressor body and is at least partially encapsulated in the casing, a mechanical seal structure is arranged around the rotating shaft between the rotating shaft and the casing at the suction end of the compressor, and the fluid medium circulation system is configured to circulate the fluid medium leaked from the mechanical seal structure.

17. The compressor according to claim 16, characterized in that The compressor also includes a heat exchanger arranged adjacent to the compressor body and a main oil supply pipeline for supplying high-temperature refrigeration oil. The second pipeline of the fluid medium circulation system transports the low-temperature fluid medium leaked from the mechanical sealing structure. The main oil supply pipeline and the second pipeline extend through the heat exchanger before being connected to the compressor body to enable the high-temperature refrigeration oil to exchange heat with the low-temperature fluid medium.

18. The compressor according to any one of claims 15 to 17, characterized in that: The reservoir is a closed tooth groove of a screw rotor of the compressor, and the second pipeline is connected to a tooth groove inlet leading to the closed tooth groove of the screw rotor.

19. A fluid machine, comprising the compressor according to any one of claims 15 to 18.

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