Screw main machine cooling structure and screw air compressor cooling system

Abstract

The utility model discloses a screw main engine cooling structure and a screw air compressor cooling system, and solves the problems that in the prior art, oil cooling of a screw air compressor main engine is insufficient, air suction and exhaust temperature is high, a screw is prone to being blocked, and energy consumption of an air compressor is increased. The cooling structure of the screw main machine comprises a screw main machine shell, an outer closed annular cavity is formed in the outer wall of the screw main machine shell, an air inlet hole and an exhaust hole are formed in the two ends of the screw main machine shell respectively, and the air inlet hole is communicated with a vortex tube. According to the cooling structure of the screw main machine, the surrounding type outer closed ring cavity is communicated with the vortex tube; and the cooling area is increased, cold air flowing out of the vortex tube enters the outer closed annular cavity, the periphery of the screw main machine is annularly wrapped and cooled, and the cooling efficiency is improved. The cooling system of the screw air compressor is composed of the multiple vortex tubes, the multiple electromagnetic reversing valves and the like and has the advantages that the temperature of air at an inlet and the temperature of a screw main machine body can be rapidly reduced, emission of hot air can be reduced through a cooling circulation system, and the cooling energy efficiency of a cooler is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of screw air compressors, in particular to a screw main engine cooling structure and a screw air compressor cooling system. Background Technique

[0002] Air compressors are widely used in various fields such as chemical industry, medicine, textile, and shipbuilding, and are an essential and important part in the production process. According to statistics, the annual electricity consumption of air compressors accounts for 8% of the national power generation. If the efficiency of each air compressor is increased by 10%, the national electricity consumption will decrease by 1%. How to reduce the energy consumption of air compressors is an urgent problem in the industry. At present, the energy saving of air compressors mainly has three aspects. One is the intake pre-treatment of the air compressor, that is, reducing the energy consumption by lowering the temperature of the inhaled air. According to research, for every 1-degree reduction, the energy consumption is reduced by 0.65%. The second is the cooling and heat recovery of the air compressor, which refers to the injection cooling and heat recovery utilization during the compression process of the air compressor, so as to reduce the energy consumption. The third is the post-treatment of compressed air, which refers to reducing the energy consumption and pressure loss on the premise of meeting the requirements of the pressure dew point.

[0003] Screw air compressors are a type of air compressor, which have the characteristics of simple structure, small vibration, low noise, high efficiency, and few vulnerable parts. In the flow rate range of 1 - 60 m 3 / min and the pressure range of ≤16 kg / cm 3 , they basically replace piston air compressors, and more than 99% of them are twin-screw air compressors. For screw air compressors, about 80% of the input energy is converted into compression heat. At present, the main engine of twin-screw air compressors is mainly cooled by oil. An oil circuit is opened in the screw main engine, and the oil and gas are mixed or the oil circuit is circulated alone to cool the oil circuit, thereby reducing the compression heat. For example, a cooling device for the lubricating oil of a screw air compressor disclosed in a Chinese patent with the publication number CN 203847391 U. However, if the intake temperature of the air compressor rises and the oil cooling is insufficient, it is easy to cause a poor working environment for the male and female rotors of the screw air compressor, easy overheating and jamming, and increased energy consumption. Therefore, it is necessary to design a screw main engine cooling system. Content of the Utility Model

[0004] In view of the deficiencies in the above background technique, the utility model provides a screw main engine cooling structure and a screw air compressor cooling system, which solve the problems in the prior art that the oil cooling of the main engine of the screw air compressor is insufficient, the intake and exhaust temperatures are high, and it is easy to cause screw jamming and increased energy consumption of the air compressor.

[0005] The technical solution of the utility model is realized as follows: A screw main engine cooling structure includes a screw main engine housing. An outer closed annular cavity is provided on the outer wall of the screw main engine housing. An intake hole and an exhaust hole are respectively provided at both ends of the screw main engine housing, and the intake hole is communicated with a vortex tube. The outer closed annular cavity surrounds the entire screw main engine, and the cold air coming out of the vortex tube enters the outer closed annular cavity to cool and lower the temperature of the screw main engine.

[0006] Further preferably, the screw main housing includes an outer housing and an outer seal cover. A ring cavity groove is formed on the outer side wall of the outer housing. The outer seal cover is hermetically connected to the outer housing to form an outer closed ring cavity for the ring cavity groove. The outer housing and the outer seal cover can be hermetically connected by welding, bolts or threaded connections to ensure the sealing performance of the outer closed ring cavity.

[0007] Further preferably, the air inlet hole is arranged on the front end face of the outer housing and communicates with the outer closed ring cavity through an L-shaped channel. The exhaust hole is arranged on the rear end face of the outer housing and communicates with the outer closed ring cavity through an L-shaped channel. Cold air enters the L-shaped channel through the air inlet hole and then enters the outer closed ring cavity for cooling. The hot air is discharged from the exhaust hole out of the outer closed ring cavity, forming an internal gas circulation in the outer closed ring cavity.

[0008] Further preferably, a screw member is arranged inside the outer housing. There are two air inlet holes on the front end face of the outer housing, namely air inlet hole A and air inlet hole B, and two exhaust holes on the rear end face of the outer housing, namely exhaust hole A and exhaust hole B. The air inlet holes correspond to the vortex tubes one by one. The structural design of two inlets and two outlets accelerates the internal gas circulation speed of the outer closed ring cavity and improves the cooling efficiency. Multiple air inlet holes and multiple exhaust holes can also be set according to needs.

[0009] A screw air compressor cooling system includes the screw main engine cooling structure described above, and also includes a post-cooler. The exhaust port of the vortex tube is connected to the post-cooler through a return pipeline. The gas coming out of the air compressor enters the vortex tube through the second supply pipeline and the electromagnetic reversing valve. The cold air discharge port of the vortex tube is connected to the outer closed ring cavity of the screw main engine cooling structure. Preferably, a proportional flow valve is arranged on the second supply pipeline.

[0010] Further preferably, at least two electromagnetic reversing valves are connected in parallel on the second supply pipeline. The electromagnetic reversing valves correspond to the vortex tubes one by one, and the air outlet of the electromagnetic reversing valve is connected to the air inlet of the vortex tube. The gas entering the vortex tube from the electromagnetic reversing valve produces cold air at one end and hot air at the other end under the action of the vortex tube. The cold air enters the screw main engine cooling structure and the hot air is directly discharged.

[0011] Further preferably, the exhaust pipe of the air compressor is connected to the first supply pipeline and the second supply pipeline through a tee. The first supply pipeline is connected to the post-cooler.

[0012] Further preferably, a temperature detector is arranged at the exhaust port of the screw main housing. The oil outlet of the screw main housing is connected to an oil-gas separator. The gas outlet of the oil-gas separator is connected to the post-cooler. The oil outlet of the oil-gas separator is connected to the oil inlet of the screw main housing through an oil cooler.

[0013] Further preferably, an air filter is connected to the air inlet of the screw main engine housing, and an air inlet valve is provided on the pipeline between the air filter and the screw main engine housing.

[0014] The beneficial effects of the present utility model are as follows: The cooling structure of the screw main engine of the present utility model adopts an encircling outer closed ring cavity connected to a vortex tube; the cooling area is increased, and the cold air flowing out of the vortex tube enters the outer closed ring cavity to conduct peripheral annular wrapping cooling on the screw main engine, improving the cooling efficiency. The cooling system of the screw air compressor of the present utility model consists of multiple vortex tubes and multiple electromagnetic reversing valves, etc., and can have the characteristics of quickly reducing the air temperature at the inlet and the body temperature of the screw main engine. The cooling circulation system can reduce the emission of hot air and increase the cooling energy efficiency of the cooler. Used in conjunction with a temperature sensor, a feedback closed-loop cooling regulation system is formed, which can effectively reduce the exhaust volume consumption of the air compressor. The present invention can effectively solve the problems of insufficient oil seal cooling, high intake and exhaust temperatures of traditional twin-screw air compressors, resulting in jamming and wear of the male and female rotors and increased energy consumption; at the same time, it has the advantages of energy conservation and environmental protection and has high practical value. Brief Description of the Drawings

[0015] In order to more clearly illustrate the embodiments of the present utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a schematic diagram of the cooling structure of the screw main engine of the present utility model.

[0017] Figure 2 It is a schematic diagram of the cooling system of the screw air compressor of the present utility model.

[0018] Figure 3 It is a schematic diagram of the structure of the vortex tube of the present utility model.

[0019] In the figure: 1 air inlet hole A, 2 outer seal cover, 3 outer housing, 4 air inlet hole B, 5 outer closed ring cavity, 6 exhaust hole A, 7 exhaust hole B, 8 cold air discharge port, 9 exhaust port, 10 air inlet, 11 vortex tube, 12 electromagnetic reversing valve, 13 proportional flow valve, 14 first air supply pipeline, 15 second air supply pipeline, 16 return pipeline, 17 aftercooler, 18 temperature detector, 19 oil-gas separator, 20 slave air compressor, 21 oil cooler, 22 air filter, 23 air inlet valve, 100 screw main engine housing, 200 screw part. Detailed Embodiments

[0020] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0021] As Figure 1 shown in Embodiment 1, a cooling structure for a screw main engine includes a screw main engine housing 100. An outer closed annular cavity 5 is provided on the outer wall of the screw main engine housing 100. An air inlet hole and an exhaust hole are respectively provided at both ends of the screw main engine housing 100, and the air inlet hole is communicated with an eddy current tube 11. The outer closed annular cavity 5 is arranged in a ring shape along the outer wall of the screw main engine housing 100 and surrounds the screw main engine, increasing the cooling area. The cold air flowing out of the eddy current tube 11 enters the outer closed annular cavity 5 to perform peripheral annular wrapping cooling on the screw main engine, improving the cooling efficiency, and solving the problems of insufficient oil seal cooling, high intake air temperature, resulting in stuck and worn male and female rotors, and increased energy consumption in traditional twin-screw air compressors.

[0022] As an implementation manner, the screw main engine housing 100 includes an outer housing 3 and an outer sealing cover 2. A ring cavity groove is opened on the outer side wall of the outer housing 3, and the outer sealing cover 2 is hermetically connected to the outer housing 3 to form the outer closed annular cavity 5 with the ring cavity groove. The cooling structure of the screw main engine is mainly composed of a closed structure formed by the screw outer housing and the outer sealing cover, that is, the outer closed annular cavity is formed. The outer sealing cover and the outer housing can be fixed by welding or threaded connection, etc., to ensure the sealing performance of the outer closed annular cavity.

[0023] Embodiment 2, a cooling structure for a screw main engine. On the basis of Embodiment 1, in this embodiment, the air inlet hole is arranged on the front end face of the outer housing 3 and is communicated with the outer closed annular cavity 5 through an L-shaped channel, and the exhaust hole is arranged on the rear end face of the outer housing 3 and is communicated with the outer closed annular cavity 5 through an L-shaped channel. The cold air enters the L-shaped channel through the air inlet hole and then enters the outer closed annular cavity for cooling, while the hot air is discharged from the exhaust hole out of the outer closed annular cavity, forming an internal gas circulation in the outer closed annular cavity.

[0024] As a preferred solution, a screw member 200 is provided inside the outer housing 3. There are two air inlets on the front end face of the outer housing 3, namely air inlet A1 and air inlet B4, and there are two air outlets on the rear end face of the outer housing 3, namely air outlet A6 and air outlet B7. The air inlets correspond to the vortex tubes 11 one by one. The structural design of two inlets and two outlets speeds up the internal gas circulation speed of the outer closed ring cavity and improves the cooling efficiency. According to needs, multiple air inlets and multiple air outlets can also be set; when multiple air inlets and multiple air outlets are selected, the number of air inlets and air outlets can be the same or different to achieve the gas circulation in the outer closed ring cavity. That is, the utility model can set multiple vortex tubes connected to the main engine cooling holes according to the different cooling powers of the screw main engine to achieve rapid cooling.

[0025] As Figure 2 , 3 shown in Embodiment 3, a screw air compressor cooling system includes the screw main engine cooling structure described in Embodiment 1 or 2, and further includes a post-cooler 17. The exhaust port 9 of the vortex tube 11 is communicated with the post-cooler 17 through a return pipeline 16. The hot air discharged from the vortex tube 11 enters the return pipeline through the exhaust port, and then enters the post-cooler for cooling through the return pipeline. The cooled hot air can be directly discharged into the atmosphere or can re-enter the screw main engine through a pipeline. The gas coming out of the air compressor 20 enters the vortex tube 11 through the second air supply pipeline 15 and the electromagnetic change-over valve 12. In this embodiment, at least two electromagnetic change-over valves 12 arranged in parallel are connected to the second air supply pipeline 15. The electromagnetic change-over valves 12 correspond to the vortex tubes 11 one by one, and the air outlet of the electromagnetic change-over valve 12 is communicated with the air inlet 10 of the vortex tube 11. The electromagnetic change-over valve can adopt a two-position two-way electromagnetic change-over valve. Two or more electromagnetic change-over valves 12 can be provided, and two or more corresponding vortex tubes can be provided. Multiple vortex tubes can be set to be connected to the main engine cooling holes according to the different cooling powers of the screw main engine to achieve rapid cooling; in this embodiment, two electromagnetic change-over valves and two vortex tubes are taken as examples. The cold air discharge port 8 of the vortex tube 11 is communicated with the outer closed ring cavity 5 of the screw main engine cooling structure; the cold air coming out of the vortex tube enters the outer closed ring cavity 5 through the cold air discharge port 8 to cool the screw main engine. A proportional flow valve 13 is provided on the second air supply pipeline 15; the proportional flow valve 13 adjusts the cold air flow rate in the second air supply pipeline 15.

[0026] In this embodiment, the exhaust pipe of the air compressor 20 is connected to a first air supply pipeline 14 and a second air supply pipeline 15 through a three-way pipe, and the first air supply pipeline 14 is communicated with the aftercooler 17. Specifically, the exhaust pipe of the air compressor is connected to a reducing three-way to divide the gas into two paths. One path is discharged through the first air supply pipeline 14 for normal air use, and the other path is connected to the intake hole of the vortex tube 11 through the second air supply pipeline 15, a proportional flow valve, and then a two-way or multi-way electromagnetic directional valve 12. The high-temperature exhaust gas of the vortex tube can be connected back to the aftercooler through a pipeline three-way. The air cooled by the aftercooler can be directly discharged into the atmosphere, or the air cooled by the aftercooler can be connected to the air supply path 15 through a one-way valve and a three-way to re-enter the screw main engine.

[0027] In this embodiment, a temperature detector 18 is provided at the exhaust port of the screw main engine housing 100. The temperature detector 18 can adopt a temperature sensor and is used to detect the temperature of the gas discharged from the screw main engine. When the temperature of the gas discharged from the screw main engine is detected to be abnormal, the electromagnetic directional valve selects multiple paths to open according to the temperature difference, timely cools the screw main engine, and at the same time avoids energy waste caused by excessive opening of the electromagnetic directional valve. The oil outlet of the screw main engine housing 100 is connected to an oil-gas separator 19. The gas outlet of the oil-gas separator 19 is communicated with the aftercooler 17, and the oil outlet of the oil-gas separator 19 is connected to the oil inlet of the screw main engine housing 100 through an oil cooler 21. The oil discharged from the screw main engine enters the oil-gas separator for oil-gas separation. The separated oil enters the oil cooler for cooling, and the cooled oil re-enters the screw main engine. The gas separated from the oil-gas separator enters the aftercooler for cooling. An air filter 22 is connected to the air inlet of the screw main engine housing 100 for filtering the air entering the screw main engine housing. An intake valve 23 is provided on the pipeline between the air filter 22 and the screw main engine housing 100, and the intake valve controls the amount of air entering the screw main engine.

[0028] The specific operation of the screw air compressor cooling system of the present utility model is as follows: Under normal operation, the motor drives the male and female rotors of the screw main engine to rotate under the action of the transmission mechanism. Thus, the compressed air passes through the air filter and the intake valve and enters the screw main engine for compression, and is discharged to the oil-gas separator after being mixed with the lubricating oil. The lubricating oil is cooled by the oil-gas separator and the oil cooler and then re-enters the screw main engine for lubrication and cooling. The air is cooled by the aftercooler and then discharged. When the temperature of the gas discharged from the screw main engine is detected to be abnormal, the electromagnetic directional valve opens multiple paths according to the temperature difference, and the proportional flow valve adjusts the flow rate of the cooling pipeline. The cold air generated by the vortex tube passes through the intake hole of the housing of the screw main engine, passes through the L-shaped channel, enters the outer closed cavity, flows from one end of the closed cavity to the other end, and then is discharged through the L-shaped channel. Thereby, the screw main engine is cooled, and the hot air discharged from the vortex tube is discharged after being cooled by the aftercooler. When the temperature returns to the normal range, the electromagnetic directional valve is closed in sequence.

[0029] The design of the multi-vortex tube and the multi-electromagnetic reversing valve can have the characteristics of quickly reducing the air temperature at the inlet of the screw main engine and the body temperature of the screw main engine. The cooling circulation system can reduce the emission of hot air and increase the cooling energy efficiency of the cooler. The feedback-regulated cooling system can reduce the consumption of the air compressor exhaust volume. The present invention can effectively solve the problems of insufficient oil seal cooling, high suction and exhaust temperatures in traditional twin-screw air compressors, which cause jamming and wear of the male and female rotors and increase energy consumption.

[0030] It should be noted that for an oil-free screw air compressor, the cooling system does not have an oil-gas separator and an oil cooler, and the system consists only of an air medium to form a compression exhaust and refrigeration cycle system.

[0031] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A screw main engine cooling structure, characterized in that: It comprises a screw main housing (100), an outer closed annular cavity (5) is provided on the outer wall of the screw main housing (100), an air inlet hole and an air outlet hole are respectively provided at two ends of the screw main housing (100), and the air inlet hole is connected to the vortex tube (11).

2. The screw main unit cooling structure according to claim 1, characterized in that: The screw main housing (100) comprises an outer shell (3) and an outer sealing cover (2); an annular cavity groove is provided on the outer side wall of the outer shell (3); the outer sealing cover (2) and the outer shell (3) are sealedly connected so that the annular cavity groove forms an outer closed annular cavity (5).

3. The screw main unit cooling structure according to claim 2, characterized in that: The air inlet hole is arranged on the front end surface of the outer shell (3) and is in communication with the outer closed annular cavity (5) through an L-shaped channel, and the air outlet hole is arranged on the rear end surface of the outer shell (3) and is in communication with the outer closed annular cavity (5) through the L-shaped channel.

4. The screw main unit cooling structure according to claim 2 or 3, characterized in that: The outer shell (3) is provided with a screw member (200), the front end surface of the outer shell (3) is provided with two air inlet holes, namely an air inlet hole A (1) and an air inlet hole B (4), and the rear end surface of the outer shell (3) is provided with two exhaust holes, namely an exhaust hole A (6) and an exhaust hole B (7), the air inlet holes corresponding to the vortex tube (11) one by one.

5. A screw air compressor cooling system, characterized in that: It comprises the screw main unit cooling structure as claimed in any one of claims 1 to 4, and also comprises an aftercooler (17), the exhaust port (9) of the vortex tube (11) is connected with the aftercooler (17) through a return pipeline (16), the gas from the air compressor (20) enters the vortex tube (11) through a second air supply pipeline (15) and an electromagnetic reversing valve (12), and the cold air exhaust port (8) of the vortex tube (11) is connected with the outer closed annular cavity (5) of the screw main unit cooling structure.

6. The screw air compressor cooling system according to claim 5, characterized in that: The second air supply pipeline (15) is provided with a proportional flow valve (13).

7. The screw air compressor cooling system according to claim 6, characterized in that: The second air supply pipeline (15) is connected to at least two electromagnetic reversing valves (12) arranged in parallel, the electromagnetic reversing valves (12) correspond to the vortex tubes (11) one by one, and the air outlets of the electromagnetic reversing valves (12) are connected to the air inlets (10) of the vortex tubes (11).

8. The screw air compressor cooling system according to claim 5, characterized in that: The exhaust pipe of the air compressor (20) is connected to a first air supply pipeline (14) and a second air supply pipeline (15) via a three-way pipe, and the first air supply pipeline (14) is connected to the aftercooler (17).

9. The screw air compressor cooling system according to claim 5 or 8, characterized in that: A temperature detector (18) is provided at the exhaust port of the screw main housing (100); the oil outlet of the screw main housing (100) is connected to an oil-gas separator (19); the air outlet of the oil-gas separator (19) is in communication with the aftercooler (17); and the oil outlet of the oil-gas separator (19) is connected to the oil inlet of the screw main housing (100) via an oil cooler (21).

10. The screw air compressor cooling system according to claim 9, characterized in that: An air filter (22) is connected to the air inlet of the screw main housing (100), and an air inlet valve (23) is provided on the pipeline between the air filter (22) and the screw main housing (100).

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