CN111707023B

CN111707023B - Bidirectional expansion valve steam-mixing super-cavitation jet noise suppression device

Info

Publication number: CN111707023B
Application number: CN202010426601.4A
Authority: CN
Inventors: 汪谦旭; 张玙; 刘益才; 李政
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2020-05-19
Filing date: 2020-05-19
Publication date: 2021-09-10
Anticipated expiration: 2040-05-19
Also published as: CN111707023A

Abstract

The invention relates to a bidirectional expansion valve steam-mixing super-cavitation jet noise suppression device; the refrigerant gas in the middle of the evaporator is introduced into the outlet of the expansion valve through the bypass capillary tube, so that the refrigerant which is discharged from the expansion valve and enters the evaporator is mixed with the steam, the local pressure of a steam mixing area is improved, the cavitation number is effectively reduced, the pressure of cavitation bubble collapse is obviously reduced, the super-cavitation phenomenon is formed, the cavitation noise is greatly reduced, and the mixed refrigerant flows into the evaporator again to complete the circulation; compared with the traditional silencer, the silencer has the advantages of simple structure, convenient processing and installation, low later maintenance cost and the like; the invention has wide application, is not only suitable for common refrigerating devices such as refrigerators, air conditioners and the like, but also can be used for refrigerating systems in the fields of machinery, metallurgy, petroleum, chemical industry, food preservation, artificial environment, biological pharmacy and the like.

Description

Bidirectional expansion valve steam-mixing super-cavitation jet noise suppression device

Technical Field

The invention designs a novel steam-mixing cavitation jet noise suppression device for a two-way expansion valve, and particularly relates to a refrigerant gas introduced into an evaporator by adding a bypass capillary tube to a connecting pipe at the outlet of an electronic expansion valve. If the electronic expansion valve is a bidirectional electronic expansion valve, the flow direction of the refrigerant is changed under different modes, both ends of the electronic expansion valve can be used as outlets, and bypass capillary tubes are required to be added at both ends of the electronic expansion valve respectively. In case of one-way expansion valve, only by-pass capillary tube is added to the outlet end, and the refrigerant gas in by-pass tube is mixed and then flows back into evaporator. Because the outlet of the electronic expansion valve can generate great jet noise, the steam mixing is carried out at the outlet of the electronic expansion valve, so that the steam mixing super-cavitation effect is achieved, the pressure of a steam mixing area can be improved, the cavitation coefficient is effectively reduced, the pressure of cavitation bubbles during collapse is obviously reduced, and the cavitation noise and the bubble bursting noise are greatly reduced.

Background

The noise research of the refrigeration system shows that besides the mechanical noise and the electromagnetic noise of the compressor, the flow noise of the system directly influences the noise level of the refrigeration system and the sound quality parameters of the refrigeration system, and the throttling jet noise, especially the bubble flow and the block flow of the refrigerant sprayed from the outlet of the electronic expansion valve, is a great important source of the noise of the refrigeration system. When the refrigerant enters the evaporator from the expansion valve, due to the influence of the change of the pipeline structure, the dryness and the flow resistance of the refrigerant, at the inlet of the evaporator, the flow section area of the refrigerant is suddenly enlarged, the flow state is in a jet shape, a plurality of vortex areas are formed in the inlet area, the pressure of the vortex areas is lower due to the sudden enlargement of the outlet section, and simultaneously, a large amount of bubbles are generated and are collapsed at a high-pressure place, so the phenomenon is called cavitation erosion, and the burst noise of the large amount of bubbles is the main reason of the noise generation at the outlet of the throttling device. Refrigerant gas with the refrigerant pressure of an evaporator inlet pipe and the middle part higher than the pressure of an expansion valve ejection outlet is introduced into the outlet of the capillary by utilizing the bypass capillary, and the super-cavitation phenomenon is formed by mixing the refrigerant gas, so that the local pressure is improved, the cavitation number is effectively reduced, the pressure of cavitation bubble collapse is obviously reduced, and the cavitation noise is greatly reduced. The effect of reducing the whole noise pollution of the refrigerating system is achieved. According to relevant theoretical knowledge of steam-mixing dynamic mechanics, engineering thermodynamics, refrigeration principle and the like, the capillary bypass is adopted, refrigerant gas in the evaporator is introduced into the outlet of the expansion valve, the steam-mixing is carried out on the outlet of the expansion valve, and the injection noise of the expansion valve is reduced, so that the effect of reducing the whole noise pollution of the refrigeration system is achieved.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: aiming at the technical problems of overlarge throttling jet noise, large integral sound power and the like of the existing refrigerating system, the silencer which does not affect the refrigerating effect and can effectively reduce the jet noise of the expansion valve is designed, is simple and easy to operate, thereby improving the sound quality of the whole refrigerating system and reducing the noise pollution.

The theoretical basis of the invention is as follows: for system expansion valve injection flow, the injection noise is mainly due to bubble popping noise. The flow speed of the gaseous refrigerant at the outlet of the expansion valve reaches the local sonic speed, a low-pressure area is formed at the outlet of the expansion valve when the gaseous refrigerant is sprayed and flows, the refrigerant can flash quickly due to sudden pressure reduction, a large number of bubbles are formed and flow along with the refrigerant liquid, the bubbles can burst suddenly along with the pressure increase, and noise is generated along with the generation of the noise. The invention mainly mixes steam in the low-pressure area of the evaporator inlet, applies the steam-mixing supercavitation theory, mixes steam in the evaporator inlet by connecting the bypass capillary tube, forms supercavitation, effectively reduces the cavitation coefficient, inhibits the generation of bubbles and simultaneously reduces the pressure of the bubbles during bursting, thereby reducing the jet noise of the refrigerant.

The technical scheme adopted by the invention is as follows: in the invention, the outlet of the expansion valve in the conventional refrigeration system is connected with the bypass capillary tube, and the refrigerant gas in the evaporator is led back to the outlet of the expansion valve by utilizing the bypass capillary tube to carry out local steam mixing to form the supercavitation phenomenon, thereby reducing the extra noise (high-frequency sharp noise caused by cavitation collapse) generated by the low local pressure at the outlet of the throttling device. The refrigerant is mixed and then flows back to the evaporator to complete the cycle.

The invention relates to a device for inhibiting jet noise of a refrigerating system by utilizing bypass capillary tube steam-mixing supercavitation, namely on the basis of ensuring a performance coefficient, in order to reduce the throttling jet noise of a refrigerating system expansion valve, a bypass tube is added on the basis of an original common refrigerating system, the bypass tube adopts a capillary tube, steam mixing is carried out at the outlet of the throttling device expansion valve, steam-mixing supercavitation is realized, the generation of bubbles and the pressure of the bubbles during collapse are reduced, the noise is inhibited from the root of the generation of the noise, the effect is more obvious than that of the traditional method, and the noise quality of the refrigerating system is improved.

The device for suppressing the steam-mixing supercavitation jet noise of the bidirectional expansion valve comprises the bidirectional expansion valve, an evaporator inlet transition pipe and 1-4 bypass capillary tubes, wherein two ends of each bypass capillary tube are communicated with the evaporator inlet transition pipe to form a bypass loop, and the distance between two ports of each bypass loop is 40-480 mm.

The bidirectional expansion valve has two functions of a one-way expansion valve throttling function and a bidirectional expansion valve throttling function; the expansion valve comprises a one-way electronic expansion valve, a thermostatic expansion valve, a two-way electronic expansion valve, a two-way thermostatic expansion valve, a one-way throttle pipe and a two-way throttle pipe, and a system provided with the throttle expansion valve has the functions of independent refrigeration, independent heating and interconversion of refrigeration heat pumps.

The refrigerant in the bidirectional expansion valve steam-mixing super-cavitation jet noise suppression device is throttled by the expansion valve and then is jetted out of the capillary tube at a high speed to enter the evaporator, at the moment, because the flow speed of the refrigerant is very high (choked flow is possibly formed, and correspondingly, the outlet speed of a gas-liquid mixture of the refrigerant is supersonic speed), local low pressure is formed at the outlet of the expansion valve, a large number of bubbles are generated, and then cavitation is carried out, and cavitation noise is generated. The refrigerant steam with slightly high pressure at the front end, the middle part and the tail part of the evaporator is introduced into the low-pressure outlet of the evaporator by utilizing the bypass capillary tube to form the air-entraining supercavitation effect at the outlet of the throttle expansion valve. The refrigerant gas-liquid is mixed and then flows back to the evaporator for evaporation, and the refrigeration cycle is completed. The connection mode of each part is oxygen welding.

The bypass capillary tubes are connected with the evaporator, the inner diameter of each bypass capillary tube is 0.5-3.5mm, the length of each bypass capillary tube extending into the evaporator is 5-250 mm, and the number of the bypass capillary tubes is 1-4.

One end of each bypass capillary tube is inserted from the tube wall above the inlet of the evaporator, the distance between the insertion opening and the inlet end is 5mm-30mm, the length is 0.5mm-5mm, a welded connection mode is adopted, one end of each bypass capillary tube is inserted from the upper part of the tube wall of the front middle part of the evaporator, the inner diameter of each bypass capillary tube is 0.5-3.5mm, the insertion length is 0.5mm-2mm, the length of each bypass capillary tube is 50mm-500mm, and the bypass capillary tubes are connected in a welded connection mode and are 1-4 in number.

The inner diameter of the evaporator pipeline is 2mm-50mm, the wall thickness is 0.5mm-3mm, and the length is 50mm-20000 mm.

One end of the expansion valve is connected with the outlet transition pipe of the condenser, and the other end of the expansion valve is connected with the inlet transition pipe of the evaporator.

The two-way expansion valve is welded at the outlet of the expansion valve and the pipe wall of the evaporator, a bypass pipe is required to be welded at the inlet and the outlet of the two-way expansion valve, the other end of the bypass pipe is connected with the pipelines of the evaporator and the condenser, and when the flow direction of the refrigerant changes, both ends of the refrigerant can be used as the outlet of the expansion valve; the expansion valve comprises a one-way electronic expansion valve and a thermostatic expansion valve, a two-way electronic expansion valve and a thermostatic expansion valve, and a one-way and two-way throttle pipe.

The material is copper tube, Bundy tube, can use in refrigerating system's metal pipeline.

The bypass capillary tube air-entrainment supercavitation device in the bidirectional expansion valve air-entrainment supercavitation jet noise suppression device can be applied to all places containing throttling jet, not only can be applied to a vapor compression type refrigeration system, but also can be applied to any system with a throttling device, and the purposes of noise reduction and silencing can be achieved.

The invention has the beneficial effects that: the invention makes full use of the theoretical basis of the steam-mixing supercavitation theory, the bubble dynamics and the like, and reduces the cavitation coefficient of the refrigerant outlet, thereby reducing the number of bubbles in the refrigerant at the outlet and obviously reducing the bubble bursting noise. The overall noise level of the refrigeration system is significantly suppressed. The invention has the advantages of simple structure, convenient processing and installation, low cost, low later maintenance cost and the like.

Drawings

FIG. 1 is a schematic diagram of a single bypass pipe steam-mixing supercavitation jet noise suppression device of the novel bidirectional expansion valve;

FIG. 2 is a schematic diagram of the novel dual bypass pipe steam-mixing supercavitation jet noise suppression device of the bidirectional expansion valve;

FIG. 3 is a schematic connection diagram of the novel dual-way expansion valve steam-mixing super-cavitation jet noise suppression device of the present invention;

in the figure: 1-electronic expansion valve coil, 2-electronic expansion valve rod, 3-electronic expansion valve body, 4-evaporator inlet transition pipe, 5-bypass capillary tube a, 6-bypass capillary tube b. 7-condenser outlet transition pipe.

Detailed Description

The invention will be further described with reference to the accompanying drawings and embodiments

Referring to fig. 1, the steam-mixing super-cavitation jet noise suppression device for the two-way expansion valve comprises an electronic expansion valve coil 1, an electronic expansion valve rod 2, an electronic expansion valve body 3, an evaporator inlet transition pipe 4, a bypass capillary tube a, wherein the outer diameter of the bypass capillary tube a is 1.8-2.5mm, the inner diameter of the bypass capillary tube a is 0.6-0.7mm, the total length of the bypass capillary tube a is 200mm, the length of the bypass capillary tube a inserted into the front end of the evaporator inlet transition pipe 4 is 10mm, and the distance from the inserted front end to the outlet of the electronic expansion valve body 3 is 10 mm; the length of the bypass capillary tube a inserted into the rear end of the evaporator inlet transition tube 4 is 10mm, the distance between the inserted rear end and the outlet of the electronic expansion valve body 3 is 170mm, and the connection mode of all parts is oxygen welding.

Referring to fig. 2, the steam-mixing super-cavitation jet noise suppression device for the bidirectional expansion valve comprises an electronic expansion valve coil 1, an electronic expansion valve rod 2, an electronic expansion valve body 3, an evaporator inlet transition pipe 4, a bypass capillary pipe a and a bypass capillary pipe b; the outer diameter of the bypass capillary tube a is 1.8-3.5mm, the inner diameter is 0.6-1.5mm, the total length of the bypass capillary tube a is 200mm, the length of the bypass capillary tube a inserted into the front end of the evaporator inlet transition tube 4 is 10mm, and the distance from the inserted front end to the outlet of the electronic expansion valve body 3 is 10 mm; the length of the bypass capillary tube a inserted into the rear end of the evaporator inlet transition tube 4 is 10mm, and the distance between the inserted rear end and the outlet of the electronic expansion valve body 3 is 170 mm; the outer diameter of the bypass capillary tube b is 1.8-3.5mm, the inner diameter is 0.6-1.5mm, the total length of the bypass capillary tube b is 400mm, the length of the bypass capillary tube b inserted into the front end of the evaporator inlet transition tube 4 is 10mm, and the distance from the inserted front end to the outlet of the electronic expansion valve body 3 is 30 mm; the length of the bypass capillary tube b inserted into the rear end of the evaporator inlet transition tube 4 is 10mm, and the distance between the inserted rear end and the outlet of the electronic expansion valve body 3 is 190 mm; the connection mode of each part is oxygen welding.

Referring to fig. 3, the steam-mixing super-cavitation jet noise suppression device for the bidirectional expansion valve comprises an electronic expansion valve coil 1, an electronic expansion valve rod 2, an electronic expansion valve body 3, an evaporator inlet transition pipe 4, a bypass capillary pipe a, a bypass capillary pipe b and a condenser outlet transition pipe; the outer diameter of the bypass capillary tube a is 1.8-3.5mm, the inner diameter is 0.6-1.5mm, the total length of the bypass capillary tube a is 200mm, the length of the bypass capillary tube a inserted into the front end of the evaporator inlet transition tube 2 is 10mm, and the distance from the inserted front end to the outlet of the electronic expansion valve body 3 is 10 mm; the length of the bypass capillary tube a inserted into the rear end of the evaporator inlet transition tube 2 is 10mm, and the distance between the inserted rear end and the inlet of the electronic expansion valve body 3 is 170 mm; the outer diameter of the bypass capillary tube b is 1.8-3.5mm, the inner diameter is 0.6-1.5mm, the total length of the bypass capillary tube b is 400mm, the length of the bypass capillary tube b inserted into the tail end of the outlet transition tube 7 of the condenser is 10mm, and the distance between the inserted front end and the inlet of the electronic expansion valve body 3 is 30 mm; the length of the bypass capillary tube b inserted into the front end of the condenser outlet transition tube 7 is 10mm, and the distance between the inserted rear end and the inlet of the electronic expansion valve body 3 is 190 mm; the connection mode of each part is oxygen welding.

The invention has wide application, is not only suitable for common refrigerating devices such as refrigerators, air conditioners and the like, but also can be used for refrigerating systems in the fields of machinery, metallurgy, petroleum, chemical industry, food preservation, artificial environment, biological pharmacy and the like.

Claims

1. The utility model provides a two-way expansion valve mixes vapour super cavitation injection noise suppression device which characterized in that: the bidirectional expansion valve steam-mixing supercavitation jet noise suppression device is characterized in that a bypass capillary tube is connected between an outlet of a throttling device, an inlet transition tube of an evaporator and the front middle part of the evaporator, so that a gaseous refrigerant with a pressure slightly higher than the jet pressure of the capillary tube in the front middle part of the evaporator flows back to the outlet of the throttling device along the bypass capillary tube to perform local steam mixing to form a supercavitation phenomenon, thereby reducing extra noise generated by low local pressure at the outlet of the throttling device, and after being converged, refrigerants in a bypass tube flow back to the inside of the evaporator to complete refrigerant circulation; the steam-mixing super-cavitation jet noise suppression device for the two-way expansion valve comprises an electronic expansion valve coil (1), an electronic expansion valve rod (2), an electronic expansion valve body (3), an evaporator inlet transition pipe (4), a bypass capillary pipe a (5), a bypass capillary pipe (6) b and a condenser outlet transition pipe (7), and is composed of the bypass capillary pipe, an auxiliary pipeline and a connecting piece; the expansion valve comprises an electronic expansion valve and a thermal expansion valve; the system provided with the throttle expansion valve has the functions of independent refrigeration, independent heating and interconversion of the refrigeration heat pump; the device for suppressing the steam-mixing supercavitation jet noise of the bidirectional expansion valve comprises the bidirectional expansion valve, an evaporator inlet transition pipe and 1-4 bypass capillary tubes, wherein two ends of each bypass capillary tube are communicated with the evaporator inlet transition pipe to form a bypass loop, and the distance between two ports of each bypass loop is 40-480 mm.

2. The steam-mixing supercavitation jet noise suppression device for the bidirectional expansion valve according to claim 1, wherein: one end of the expansion valve is connected with the outlet transition pipe of the condenser, and the other end of the expansion valve is connected with the inlet transition pipe of the evaporator.

3. The steam-mixing supercavitation jet noise suppression device for the bidirectional expansion valve according to claim 1, wherein: the inner diameter of the evaporator pipeline is 2mm-50mm, the wall thickness is 0.5mm-3mm, and the length is 50mm-20000 mm.

4. The steam-mixing supercavitation jet noise suppression device for the bidirectional expansion valve according to claim 1, wherein: the bypass capillary tubes are connected with the evaporator, the inner diameter of each bypass capillary tube is 0.5-3.5mm, the length of each bypass capillary tube extending into the evaporator is 5-250 mm, and the number of the bypass capillary tubes is 1-4; the outer diameter of the bypass capillary tube a is 1.8-3.5mm, the inner diameter of the bypass capillary tube a is 0.6-1.5mm, the total length of the bypass capillary tube a is 200mm, the length of the bypass capillary tube a inserted into the front end of the evaporator inlet transition tube is 10mm, and the distance between the inserted front end and the outlet of the electronic expansion valve body is 10 mm; the length of the bypass capillary tube a inserted into the rear end of the evaporator inlet transition tube is 10mm, and the distance between the inserted rear end and the outlet of the electronic expansion valve body is 170 mm; the outer diameter of the bypass capillary tube b is 1.8-3.5mm, the inner diameter of the bypass capillary tube b is 0.6-1.5mm, the total length of the bypass capillary tube b is 400mm, the length of the bypass capillary tube b inserted into the front end of the evaporator inlet transition tube is 10mm, and the distance between the inserted front end and the outlet of the electronic expansion valve body is 30 mm; the length of the bypass capillary tube a inserted into the rear end of the evaporator inlet transition tube is 10mm, and the distance between the inserted rear end and the outlet of the electronic expansion valve body is 190 mm.

5. The steam-mixing supercavitation jet noise suppression device for the bidirectional expansion valve according to claim 1, wherein: one end of each bypass capillary tube is inserted from the upper tube wall of the evaporator inlet transition tube, the distance between an insertion opening and an inlet end is 5mm-30mm, the length is 0.5mm-5mm, a welded connection mode is adopted, one end of each bypass capillary tube is inserted from the upper portion of the front middle tube wall of the evaporator, the inner diameter of each bypass capillary tube is 0.5-3.5mm, the insertion length is 0.5mm-2mm, the length of each bypass capillary tube is 50mm-500mm, and the bypass capillary tubes are connected in a welded connection mode and are 1-4 in number.

6. The steam-mixing supercavitation jet noise suppression device for the bidirectional expansion valve according to claim 1, wherein: the inlet and the outlet of the two-way expansion valve need to be welded with bypass pipes, the other end of each bypass pipe is connected with the pipelines of the evaporator and the condenser, and when the flow direction of the refrigerant changes, both ends of the refrigerant can be used as the outlets of the two-way expansion valve.

7. The steam-mixing supercavitation jet noise suppression device for the bidirectional expansion valve according to claim 1, wherein: the connection mode adopts a rock ring or is welded together; the outlet of the throttle expansion valve is welded with the evaporator through a transition pipe; the bypass capillary steam-mixing supercavitation device can be applied to all throttling injection places, including a steam compression refrigeration system and any system with a throttling device.

8. The steam-mixing supercavitation jet noise suppression device for the bidirectional expansion valve according to claim 1, wherein: when the flow of the refrigerant is large, the steam mixing amount can be increased by increasing the number of the bypass capillaries, so that the steam mixing supercavitation phenomenon is ensured to be realized; thereby ensuring the effect of noise suppression when the refrigerant flow rate is changed.