CN113606809A

CN113606809A - Axial flow type self-circulation type gas wave refrigerating device and method

Info

Publication number: CN113606809A
Application number: CN202110918267.9A
Authority: CN
Inventors: 胡大鹏; 赵一鸣; 刘凤霞; 李毅超; 于洋
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2021-08-11
Filing date: 2021-08-11
Publication date: 2021-11-05
Anticipated expiration: 2041-08-11
Also published as: CN113606809B

Abstract

The invention discloses an axial flow type self-circulation type gas wave refrigerating device and a method. The invention can recycle the compression work output by the expansion of the high-pressure gas, and the gas after the expansion is pressurized again, and the device finally obtains medium-pressure low-temperature produced gas with certain pressure through the cooler and the heat exchanger, thereby improving the refrigeration temperature drop under the fixed pressure ratio. The axial-flow self-circulation type gas wave refrigerating machine which is a core component of the device is provided with a multi-stage fan structure, and the defect that the traditional self-pressurization gas wave refrigerating device needs to drive a fan to realize gas circulation is overcome. The number of stages of the built-in fan can be adjusted according to the requirement of the circulating driving force; the interstage connecting section adopts a multilayer baffle plate type, so that the gas dynamic pressure can be effectively recovered, and the interstage flow loss is reduced. The invention can be widely applied to the fields of cryogenic air supply, natural gas dehydration, heavy hydrocarbon removal and the like.

Description

Axial flow type self-circulation type gas wave refrigerating device and method

Technical Field

The invention relates to the technical field of gas expansion refrigeration, in particular to an axial flow type self-circulation gas wave refrigeration device and method.

Background

The gas wave refrigeration technology is a high-efficiency pressure energy comprehensive utilization technology for realizing gas expansion refrigeration by utilizing gas pressure waves such as shock waves and expansion waves to exchange energy among gases, and is mainly applied to the fields of cryogenic gas source supply, natural gas dehydration, heavy hydrocarbon removal and the like. Common gas expansion refrigeration equipment comprises an expander, a throttle valve and the like, wherein the expander has high efficiency, but has high rotating speed, poor liquid carrying capacity and high processing and maintenance cost; although the throttle valve is static equipment, the throttle valve has a simple structure and low processing and maintenance costs, but has low efficiency.

In comparison, the air wave refrigerator has the characteristics of simple structure, large liquid holdup, easy maintenance and the like, and the refrigerating efficiency is relatively high, such as a patent axial-flow type self-pressurization air wave refrigerating device, a refrigerating method CN103206801A, a radial-flow type self-pressurization air wave refrigerating device CN103206800A and the like. However, the aforesaid special use needs external fan to provide drive power in order to realize that low pressure low temperature gas is by the gas cycle process of runner exhaust, heat transfer, transformation low pressure normal atmospheric temperature gas return flow way, has defects such as the difficult regulation of driving force, device structure is complicated and occupation space is great. Therefore, it is a technical problem to be solved by those skilled in the art to provide a self-circulation type air wave refrigerating apparatus which can recover pressure energy, has a simple structure, and is easy to adjust.

Disclosure of Invention

The invention aims to provide an axial flow type self-circulation type gas wave refrigerating device and method, which can recover gas pressure energy while performing expansion refrigeration, can realize low-pressure gas self-circulation without external equipment, and can effectively solve the technical problems.

The technical scheme of the invention is as follows:

the invention provides an axial flow type self-circulation type gas wave refrigerating device which consists of an air inlet pressure regulating valve, an axial flow self-circulation type gas wave refrigerating machine, a cooler, a heat exchanger and a gas production pressure regulating valve, and the specific working method of the invention is as follows: the high-pressure inlet air for expansion refrigeration firstly flows through the inlet air pressure regulating valve and then enters the high-pressure cavity of the axial flow self-circulation type gas wave refrigerator from the high-pressure inlet port of the axial flow self-circulation type gas wave refrigerator, and the high-pressure inlet air pressure entering the axial flow self-circulation type gas wave refrigerator can be regulated by the inlet air regulating valve, so that the equipment can meet different refrigeration temperature drop requirements. High-pressure inlet air in the high-pressure cavity can enter a rotary drum flow channel which is communicated with the high-pressure nozzle through the injection of the high-pressure nozzle, and the high-pressure inlet air can output expansion function while expanding and cooling to supply energy for incident shock waves so as to compress original gas in the flow channel, so that the original low-pressure normal-temperature gas in the flow channel is heated and pressurized into medium-pressure high-temperature gas, and the recovery of pressure energy is realized. When the flow channel continues to rotate to be communicated with a medium-pressure nozzle on the shell, medium-pressure high-temperature gas is discharged into the medium-pressure cavity from the medium-pressure nozzle and then is discharged into the cooler from the medium-pressure exhaust port for cooling, and heat obtained in the compression process is consumed. The low-pressure low-temperature gas formed by the expansion of the high-pressure gas in the flow channel is discharged out of the flow channel and is discharged into the heat exchanger through the low-pressure exhaust port of the axial flow self-circulation type gas wave refrigerator under the drive of the multi-stage built-in fan of the axial flow self-circulation type gas wave refrigerator, and is subjected to cold quantity exchange with the medium-pressure normal-temperature gas discharged by the cooler to obtain the medium-pressure low-temperature gas as a product of the device, and the gas pressure can be adjusted by the gas production pressure adjusting valve, so that different process requirements are met. The low-pressure low-temperature gas transmitted by the cold quantity is converted into low-pressure normal-temperature gas, and the low-pressure low-temperature gas is returned to the axial flow self-circulation type gas wave refrigerator from the low-pressure gas return port of the axial flow self-circulation type gas wave refrigerator under the drive of the multi-stage built-in fan of the axial flow self-circulation type gas wave refrigerator to realize self circulation, so that the low-pressure low-temperature gas in the runner of the rotary drum is pushed to be discharged.

The device realizes the recovery of the expansion function of the high-pressure gas by utilizing the shock wave pressurization, and transmits the cold energy obtained by the expansion of the high-pressure gas to the medium-pressure gas obtained by boosting through the heat exchanger, so that the device can finally obtain the low-temperature gas with medium-pressure, the refrigeration depth of the device under the total inlet-outlet pressure ratio is greatly improved, the integral working efficiency of the equipment is improved, and the waste of the pressure is avoided.

The invention adopts a multi-stage built-in fan structure, low-pressure normal-temperature return air discharged by a suction heat exchanger returns to an axial-flow self-circulation type air wave refrigerator, and the low-pressure normal-temperature return air firstly enters a first-stage fan impeller to carry out centrifugal pressurization and then enters a fan volute of a first-stage fan diffuser to carry out dynamic pressure recovery. In the volute of the fan, partial aerodynamic pressure is converted into static pressure, so that the return air pressure is increased, and the air flow loss is reduced. Because the fans at all stages are sequentially arranged from bottom to top along the axial direction, return air can turn and flow at the outlet of the first-stage volute and still has high speed component along the tangential direction of the outlet of the volute. The flow direction of the return air flowing into the lower-level fan is from the outer ring to the inner ring, the flow sectional area is gradually reduced, and in order to avoid the pressure energy being converted into the speed energy again, the multi-layer baffle is arranged in the interstage diffuser of the fan diffuser, so that the return air flowing into the interstage diffuser is always divided into a plurality of streams in the flowing process towards the inner ring, a larger total flow area is kept, the air flow speed is controlled, the flow loss in the fan is reduced, and the overall efficiency of the self-circulation system is improved.

And after flowing out of the first-stage interstage diffuser, return air boosted by one stage sequentially flows into each stage of built-in fans, the boosting process and principle of each stage are the same as those of the first stage, and the return air enters the cavity and flows into the rotary drum flow channel from a return air guide port arranged on the equipment shell after completing dynamic pressure recovery in the fan volute when flowing out of the last-stage fan impeller and entering the last-stage fan diffuser, so that the last-stage interstage diffuser is not arranged any more.

The invention provides driving force for low-pressure gas self-circulation through the built-in fans at each stage, and because the flow loss between stages can be effectively reduced under the speed reduction and guide effects of the fan diffuser, the diameter of the equipment can be effectively controlled by adjusting the stage number of the fans to enable the equipment to meet the pressurization requirement, and the efficiency of the self-circulation system cannot be obviously influenced. All levels of fans are sequentially installed along the axial direction, are in close contact with each other but are kept relatively independent, and the fan structure has the advantages of compact structure, convenience in assembly, easiness in replacement and the like.

The impeller blades of the fan at each stage can adopt different structural sizes and bending types according to the treatment capacity and the requirement of the circulating driving force. The structural form and the size of each stage of fan diffuser can be respectively designed, wherein the number of the volutes can be set to be a plurality, and the number of baffle layers, the number of single-layer baffles and the bending form of the baffles in the interstage diffuser can be adjusted step by step according to the air flow condition.

The invention has the advantages of

The invention can recover the expansion work output by the high-pressure gas during the expansion refrigeration by utilizing the shock wave pressurization effect, thereby leading the device to obtain higher refrigeration depth under the fixed expansion ratio. The axial flow self-circulation type gas wave refrigerator is provided with a multi-stage built-in fan structure, and the structure can provide driving force for the gas circulation process of discharging, heat exchanging and converting low-pressure low-temperature gas into a low-pressure normal-temperature gas return flow channel in the refrigeration method, so that the device can be effectively simplified, and the size and the floor area of equipment can be reduced; the number of stages of the built-in fan, the form of fan impeller blades, the size and the number of diffusion volutes of the fan diffuser, the form and the number of layers of baffles of the interstage diffuser and the like can be designed and adjusted according to the requirements of the circulating driving force and the size of equipment, and the fan diffuser has the advantages of high working efficiency, large working condition adaptation range, convenience in installation and maintenance and the like.

Drawings

FIG. 1 is a schematic flow diagram of an axial flow self-circulating gas wave refrigeration process;

FIG. 2 is a schematic view of an axial-flow self-circulating gas wave refrigerator;

FIG. 3 is a schematic diagram of a blower volute, wherein a is a sectional view taken along line A-A in FIG. 2, and b-h are schematic diagrams of single-stage blower volutes with different volute numbers;

FIG. 4 is a cross-sectional view B-B of FIG. 2, showing the interstage diffuser;

FIG. 5 is a schematic view of an internal fan configuration and gas flow process;

figure 6 is a schematic view of a high pressure chamber.

In the figure: 1 air inlet pressure regulating valve, 2 high pressure inlet port, 3 axial flow self-circulation type gas wave refrigerator, 4 low temperature exhaust port, 5 gas production pressure regulating valve, 6 heat exchanger, 7 cooler, 8 low pressure return air port, 9 medium pressure exhaust port, 10 upper bearing, 11 high pressure nozzle, 12 shell, 13 medium pressure nozzle, 14 lower bearing, 15 lower bearing gland, 16 first stage fan impeller, 17 lower head, 18 fan gland, 19 first stage fan diffuser, 20 last stage fan impeller, 21 last stage fan diffuser, 22 return air flow guiding port, 23 rotating drum flow channel, 24 rotating drum, 25 main shaft, 26 high pressure cavity, 27 upper bearing gland, 28 low temperature cavity, 29 low pressure return air cavity, 30 medium pressure cavity, 191 fan volute, 192 interstage diffuser.

Detailed Description

The present invention relates to an axial flow type self-circulation type gas wave refrigerating device and method, wherein a typical embodiment is described as follows, but not limited to the embodiment:

the axial flow type self-circulation type gas wave refrigerating device shown in fig. 1 mainly comprises an air inlet pressure regulating valve 1, an axial flow self-circulation type gas wave refrigerator 3, a cooler 7, a heat exchanger 6 and a gas production pressure regulating valve 5. The axial flow self-circulation type gas wave refrigerator 3 is provided with four pressure ports such as a high-pressure air inlet port 2, a low-temperature air outlet port 4, a low-pressure air return port 8 and a medium-pressure air outlet port 9. Wherein, the high-pressure air inlet port 2 is connected with the air inlet pressure regulating valve 1; the low-temperature exhaust port 4 is connected with a low-pressure air inlet of the heat exchanger 6; the low-pressure air return port 8 is connected with a low-pressure exhaust port of the heat exchanger 6; the medium-pressure exhaust port 9 is connected with a medium-pressure air inlet of the cooler 7; a medium-pressure exhaust port of the cooler 7 is connected with a medium-pressure air inlet of the heat exchanger 6; the medium-pressure exhaust port of the heat exchanger 6 is connected with the gas production pressure regulating valve 5.

As shown in fig. 2, a rotary drum 24 driven by a main shaft 25 to rotate is arranged in a housing 12 of the axial flow self-circulation type gas wave refrigerator 3, the rotary drum 24 is composed of flow channels 23 with two ends communicated uniformly, each flow channel 23 is separated by a flow channel partition plate, and the flow channels 23 are not communicated with each other. A closed high-pressure cavity 26 (shown in fig. 6) with a high-pressure nozzle 11 is arranged at the upper end of the rotary drum 24, the high-pressure cavity 26 is communicated with the high-pressure air inlet port 2, and the outer side of the top of the high-pressure cavity 26 is fixed on the shell 12 through bolts; the space between the rest part of the upper end of the rotary drum 24 and the shell 12 is a low-temperature cavity 28, and the low-temperature cavity 28 is communicated with the low-temperature exhaust port 4. An upper bearing 10 and a lower bearing 14 are respectively arranged in the upper end plate and the lower end plate of the shell 12 and used for fixing the main shaft 25, and the two bearings are respectively limited by an upper bearing gland 27 and a lower bearing gland 15. The middle part in the shell 12 is provided with a medium pressure cavity 30 connected with the medium pressure exhaust port 9, the top of the medium pressure cavity 30 is provided with a medium pressure nozzle 13, and the medium pressure cavity 30 is positioned at the lower end of the rotary drum 24. The space between the remainder of the lower end of drum 24 and housing 12 is a low pressure return air chamber 29. The lower end enclosure 17 is fixed on the lower end plate of the shell 12 through bolts, and a multi-stage built-in fan is arranged between the lower end enclosure 17 and the lower end plate of the shell 12; the multistage built-in fan includes a last-stage built-in fan composed of a last-stage fan diffuser 21 and a last-stage fan impeller 20, a first-stage built-in fan composed of a first-stage fan diffuser 19 and a first-stage fan impeller 16, and middle built-in fans at each stage. The lower end plate of the housing 12 is provided with a return air guide port 22, so that air pushed by an internal fan enters a low-pressure return air chamber 29 and then flows into a flow passage 23 of the rotary drum 24.

After the high-pressure inlet air is adjusted to the pressure required by the device by the inlet pressure adjusting valve 1, the high-pressure inlet air enters a high-pressure cavity 26 of the axial flow self-circulation type air wave refrigerator 3 through the high-pressure inlet port 2 and then is sprayed into a rotary drum flow channel 23 through the high-pressure nozzle 11 to be expanded to form low-pressure low-temperature air; original gas in a flow passage 23 of the rotary drum 24 is compressed and boosted into medium-pressure high-temperature gas by expansion work output by high-pressure gas expansion, is discharged into a medium-pressure cavity through a medium-pressure nozzle 13 on the shell 12, and is discharged into the cooler 7 through a medium-pressure exhaust port 9 to be consumed, so that heat obtained in the compression process is converted into medium-pressure normal-temperature gas; driven by a multistage built-in fan of the axial flow self-circulation type gas wave refrigerator 3, low-pressure low-temperature gas in the flow channel 23 is discharged into the heat exchanger 6 from the low-temperature exhaust port 4 and exchanges cold energy with medium-pressure normal-temperature gas discharged from the cooler 7 to obtain a product, namely medium-pressure low-temperature gas, of the device, and the gas pressure of the medium-pressure low-temperature gas can be adjusted by the gas production pressure adjusting valve 5; the low-pressure low-temperature gas transmitted by the cold quantity is converted into low-pressure normal-temperature gas, and the low-pressure normal-temperature gas is returned into the axial-flow self-circulation type gas wave refrigerator 3 through the low-pressure gas return port 8 under the drive of the multistage built-in fan to realize self circulation, so that the low-pressure low-temperature gas in the flow channel 23 is pushed to be discharged.

Each stage of built-in fan is composed of a group of fan diffusers and fan impellers, the number of stages of the built-in fan is 1-10, the specific number of stages is determined according to the requirement of self-circulation driving force, and the built-in fan can be adjusted according to the change of working conditions in the application process of the device. As shown in fig. 3 and 5, the blades of the fan impeller at each stage can be bent forward or backward along the rotation direction of the impeller, and the bending form can be a continuous smooth line such as an arc, a power function curve, an exponential function curve and the like; the angle ranges of the inlet angle and the outlet angle of the blade are both 0-180 degrees; the height of the blade is 5 mm-500 mm, and the specific value is determined according to the equipment throughput. In each stage of built-in fan, except for the last stage of fan diffuser 21, the remaining stages of fan diffusers are composed of a fan volute 191 shown in fig. 3 and an inter-stage diffuser 192 shown in fig. 4, and the last stage of fan diffuser 21 is only a fan volute. The blower volute 191 and the interstage diffuser 192 may be integrated or separated and fixed by bolts. The volute shape 191 of each stage of fan diffuser is an Archimedes spiral line type with the sectional area from small to large, and the number of single-stage volutes is 1-8. The interstage diffuser 192 is provided with 2-9 layers of baffles, so that the number of the flow fields is divided into 2-9 layers in the radial direction, and the number of the flow strands of the single-stranded fluid divided by the baffle plate in each flow field is 2-4; the height of the interstage diffuser 192 is 5 mm-500 mm, and the specific value is determined by the equipment handling capacity and the fan volute outflow angle of the previous stage.

Each stage of fan diffuser is located on the outer side of the corresponding fan impeller and is not in contact with the fan impeller, and the distance between the innermost end of the fan volute and the outermost end with the largest diameter of the fan impeller is 0.05-10 mm. The last stage of fan diffuser 21 of the equipment is fixed on the lower end plate of the shell 12, the first stage of fan diffuser 19 is clamped between the seal head 17 and the next stage of fan diffuser, and the middle stage of fan diffuser is clamped between the front stage of fan diffuser and the rear stage of fan diffuser. The fan impellers of all levels of the equipment are connected with a main shaft 25 through a flat key, the last level fan impeller 20 is pressed and fixed on the shaft shoulder of the main shaft 25 by the upper level impeller, the first level fan impeller 16 is clamped and fixed between the fan gland 18 of the built-in fan whole body and the next level fan impeller, and the middle level fan impeller is clamped and fixed between the fan impellers of the front level and the fan impeller of the rear level.

As shown in fig. 5, the flow process of the low-pressure normal-temperature gas discharged from the heat exchanger 6 in the built-in fan is as follows: the low-pressure normal-temperature return air firstly enters the inner end with the smallest diameter of the first-stage fan impeller 16 from the low-pressure return air port 8, is discharged from the outer end with the largest diameter of the impeller after the centrifugal pressurization effect of the first-stage impeller 16, then enters the first-stage fan diffuser 19 to convert partial kinetic energy into pressure energy, and then enters the second-stage fan to carry out the pressurization and dynamic pressure recovery processes which are the same as those of the first stage. The flow process of the air in the other stages of fans is the same as that of the air in the other stages of fans, and the return air enters the low-pressure return air cavity of the equipment through the return air guide opening 22 arranged on the shell 12 and then flows into the flow channel 23 of the rotary drum 24 after being discharged by the diffuser 21 of the last stage of fan.

The form and the geometric dimension of each stage of built-in fan impeller blades and the form and the dimension of the diffuser are relatively independent, and all the parts can be completely consistent or different.

Claims

1. The axial flow self-circulation type gas wave refrigerating device is characterized by mainly comprising an air inlet pressure regulating valve (1), an axial flow self-circulation type gas wave refrigerating machine (3), a cooler (7), a heat exchanger (6) and a gas production pressure regulating valve (5);

the axial flow self-circulation type gas wave refrigerator (3) is provided with a high-pressure air inlet port (2), a low-temperature air outlet port (4), a low-pressure air return port (8) and a medium-pressure air outlet port (9); wherein, the high-pressure air inlet port (2) is connected with the air inlet pressure regulating valve (1); the low-temperature exhaust port (4) is connected with a low-pressure air inlet of the heat exchanger (6); the low-pressure air return port (8) is connected with a low-pressure exhaust port of the heat exchanger (6); the medium-pressure exhaust port (9) is connected with a medium-pressure air inlet of the cooler (7); a medium-pressure exhaust port of the cooler (7) is connected with a medium-pressure air inlet of the heat exchanger (6); a medium-pressure exhaust port of the heat exchanger (6) is connected with a gas production pressure regulating valve (5);

a rotary drum (24) driven by a main shaft (25) to rotate is arranged in a shell (12) of the axial flow self-circulation type gas wave refrigerator (3), the rotary drum (24) is composed of uniformly distributed through flow passages (23) at two ends, each flow passage (23) is separated by a flow passage partition plate, and the flow passages (23) are not communicated with each other; a high-pressure cavity (26) with a high-pressure nozzle (11) is arranged at the upper end of the rotary drum (24), the high-pressure cavity (26) is communicated with the high-pressure air inlet port (2), and the outer side of the top of the high-pressure cavity (26) is fixed on the shell (12) through a bolt; the space between the rest part of the upper end of the rotary drum (24) and the shell (12) is a low-temperature cavity (28), and the low-temperature cavity (28) is communicated with the low-temperature exhaust port (4); an upper bearing (10) and a lower bearing (14) are respectively arranged in an upper end plate and a lower end plate of the shell (12) and used for fixing a main shaft (25), and the two bearings are respectively limited by an upper bearing gland (27) and a lower bearing gland (15); a medium-pressure cavity (30) connected with a medium-pressure exhaust port (9) is arranged in the middle of the inside of the shell (12), a medium-pressure nozzle (13) is arranged at the top of the medium-pressure cavity (30), and the medium-pressure cavity (30) is positioned at the lower end of the rotary drum (24); the space between the rest part of the lower end of the rotary drum (24) and the shell (12) is a low-pressure air return cavity (29); the lower end enclosure (17) is fixed on a lower end plate of the shell (12) through bolts, and a multi-stage built-in fan is arranged between the lower end enclosure (17) and the lower end plate of the shell (12); the built-in fans comprise a last-stage built-in fan consisting of a last-stage fan diffuser (21) and a last-stage fan impeller (20), a first-stage built-in fan consisting of a first-stage fan diffuser (19) and a first-stage fan impeller (16), and middle built-in fans at all stages; an air return guide opening (22) is arranged on the lower end plate of the shell (12), so that air pushed by a built-in fan enters a low-pressure air return cavity (29) and then flows into a flow channel (23) of the rotary drum (24).

2. The axial-flow self-circulation type gas wave refrigerating device according to claim 1, wherein the number of built-in fans is 1-10, and each stage of built-in fan is composed of a set of fan diffuser and fan impeller; in each stage of built-in fans, except the last stage of fan diffuser (21), the rest of each stage of fan diffuser consists of a fan volute (191) and an interstage diffuser (192), and the last stage of fan diffuser (21) is only the fan volute; the fan volute (191) and the interstage diffuser (192) can be of an integral structure or of a split structure and are fixedly connected through bolts.

3. The axial-flow self-circulation type gas wave refrigerating device according to claim 1 or 2, wherein each stage of fan diffuser is located outside the corresponding fan impeller and is not in contact with the fan impeller, and the distance between the innermost end of the fan volute and the outermost end with the largest diameter of the fan impeller is 0.05-10 mm; the last stage of fan diffuser (21) is fixed on the lower end plate of the shell (12), the first stage of fan volute (19) is clamped between the seal head (17) and the next stage of fan diffuser, and the middle stage of fan diffuser is clamped between the front and rear stages of fan diffusers; the fan impellers of all levels are connected with a main shaft (25) through flat keys, the fan impeller (20) of the last level is fixedly pressed on a shaft shoulder of the main shaft (25) by the upper level impeller, the fan impeller (16) of the first level is fixedly clamped between a fan gland (18) of the built-in fan whole body and the fan impeller of the next level, and the fan impeller of the middle level is fixedly clamped between the fan impellers of the front level and the fan impeller of the rear level.

4. The axial-flow self-circulation type gas wave refrigerating device according to claim 1 or 2, wherein the blades of the fan impellers of each stage can be bent forwards or backwards along the rotation direction of the impellers, and the bending form can be a continuous smooth line type of an arc, a power function curve or an exponential function curve; the angle ranges of the inlet angle and the outlet angle of the blade are both 0-180 degrees; the height of the blade is 5 mm-500 mm.

5. The axial-flow self-circulation type gas wave refrigerating device according to claim 3, wherein blades of each stage of fan impeller can be bent forward or backward along the rotation direction of the impeller, and the bending form can be a circular arc, a power function curve or a continuous smooth line of an exponential function curve; the angle ranges of the inlet angle and the outlet angle of the blade are both 0-180 degrees; the height of the blade is 5 mm-500 mm.

6. The axial-flow self-circulation type air wave refrigerating device according to claim 1, 2 or 5, wherein the volute shape (191) of each stage of fan diffuser is an Archimedes spiral type with the sectional area from small to large, and the number of single-stage volutes is 1-8; the interstage diffuser (192) is provided with 2-9 layers of baffles, so that the number of the flow fields is divided into 2-9 layers in the radial direction, and the number of the flow strands of a single-stranded fluid divided by the baffle plate in each flow field is 2-4; the height of the interstage diffuser (192) is 5 mm-500 mm.

7. The axial-flow self-circulation type gas wave refrigerating device according to claim 3, wherein the volute shape (191) of each stage of fan diffuser is an Archimedes spiral line type with the sectional area from small to large, and the number of single-stage volutes is 1-8; the interstage diffuser (192) is provided with 2-9 layers of baffles, so that the number of the flow fields is divided into 2-9 layers in the radial direction, and the number of the flow strands of a single-stranded fluid divided by the baffle plate in each flow field is 2-4; the height of the interstage diffuser (192) is 5 mm-500 mm.

8. The axial-flow self-circulation type gas wave refrigerating device according to claim 4, wherein the volute shape (191) of each stage of fan diffuser is an Archimedes spiral line type with the sectional area from small to large, and the number of single-stage volutes is 1-8; the interstage diffuser (192) is provided with 2-9 layers of baffles, so that the number of the flow fields is divided into 2-9 layers in the radial direction, and the number of the flow strands of a single-stranded fluid divided by the baffle plate in each flow field is 2-4; the height of the interstage diffuser (192) is 5 mm-500 mm.

9. A refrigeration method of the axial flow self-circulation type gas wave refrigeration apparatus according to claim 1 to 8, characterized in that: after the high-pressure inlet air is adjusted to the pressure required by the device by the inlet pressure adjusting valve (1), the high-pressure inlet air enters a high-pressure cavity (26) of the axial flow self-circulation type air wave refrigerator (3) from the high-pressure inlet port (2), and is sprayed into a rotary drum flow channel (23) through a high-pressure nozzle (11) to expand to form low-pressure low-temperature gas; original gas in a flow passage (23) of the rotary drum (24) is compressed and boosted into medium-pressure high-temperature gas by expansion work output by high-pressure gas expansion, discharged into a medium-pressure cavity (30) through a medium-pressure nozzle (13) on a shell (12), and discharged into a cooler (7) through a medium-pressure exhaust port (9) to consume heat obtained in the compression process to form medium-pressure normal-temperature gas; under the drive of a built-in fan of the axial flow self-circulation type gas wave refrigerator (3), low-pressure low-temperature gas in a flow channel (23) is discharged into a heat exchanger (6) from a low-temperature exhaust port (4) and exchanges cold energy with medium-pressure normal-temperature gas discharged from a cooler (7) to obtain a product medium-pressure low-temperature gas of the device, and the gas pressure of the medium-pressure low-temperature gas can be adjusted by a gas production pressure adjusting valve (5); the low-pressure low-temperature gas transmitted by the cold energy is converted into low-pressure normal-temperature gas, and the low-pressure normal-temperature gas returns to the axial-flow self-circulation type gas wave refrigerator (3) through the low-pressure gas return port (8) under the drive of a multistage built-in fan to realize self circulation and push the low-pressure low-temperature gas in the flow channel (23) to be discharged.

10. The axial-flow self-circulation type air wave refrigerating method according to claim 9, wherein the flow process of the low-pressure normal-temperature air discharged from the heat exchanger (6) in the built-in fan is as follows: low-pressure normal-temperature gas firstly enters the inner end with the smallest diameter of a first-stage fan impeller (16) from a low-pressure gas return port (8), is discharged from the outer end with the largest diameter of the impeller after the centrifugal pressurization effect of the first-stage impeller (16), then enters a first-stage fan diffuser (19) to convert part of kinetic energy into pressure energy, and then enters a second-stage fan to carry out the same pressurization and dynamic pressure recovery processes as the first stage; the flowing process of the air in the other stages of fans is the same as the above, and the return air is discharged by the last stage of fan diffuser (21), enters the low-pressure return air cavity (29) of the equipment through the return air guide opening (22) arranged on the shell (12) and then flows into the flow passage (23) of the rotary drum (24).