CN114136023A

CN114136023A - Evaporator, manufacturing method of evaporator and refrigeration system with evaporator

Info

Publication number: CN114136023A
Application number: CN202111479493.8A
Authority: CN
Inventors: 熊从贵; 林通; 何静; 金琦
Original assignee: Taizhou Longjiang Chemical Machinery Technology Co ltd
Current assignee: Taizhou Longjiang Chemical Machinery Technology Co ltd
Priority date: 2021-12-06
Filing date: 2021-12-06
Publication date: 2022-03-04
Anticipated expiration: 2041-12-06
Also published as: CN114136023B

Abstract

The invention discloses an evaporator, which belongs to the technical field of refrigeration and comprises a tubular shell, an upper sealing plate, a lower sealing plate, an upper sealing body and a lower sealing body, wherein the upper end and the lower end of the tubular shell are respectively sealed by the upper sealing body and the lower sealing body; an upper sealing plate is arranged between the tubular shell and the upper sealing body, a lower sealing plate is arranged between the tubular shell and the lower sealing body, and the upper sealing plate, the tubular shell and the lower sealing plate form a heat exchange cavity; a braided central column is axially arranged in the cavity; and a plurality of layers of spiral pipes are arranged around the outer side of the central column. The invention discloses a manufacturing method of a corresponding evaporator and a refrigeration system based on the evaporator. The invention improves the heat transfer performance of the evaporator by arranging the multilayer spiral pipe and the gas-liquid separation chamber, reduces the detection cost of the evaporator by a corresponding manufacturing process, and obtains a refrigeration system with a simpler structure by utilizing the evaporator.

Description

Evaporator, manufacturing method of evaporator and refrigeration system with evaporator

Technical Field

The invention belongs to the technical field of refrigeration, relates to an evaporator, and particularly relates to an evaporator, a manufacturing method of the evaporator and a refrigeration system with the evaporator.

Background

In the application of refrigeration technology, high-temperature fluid and low-temperature fluid exchange heat in a heat exchanger through a metal wall surface, the low-temperature fluid absorbs the heat of the high-temperature fluid to evaporate, and the temperature of the high-temperature fluid is reduced. The low-temperature fluid enters the heat exchanger in a liquid phase, is evaporated in the heat exchanger, and the evaporated refrigerant gas enters the compressor for compression and condensation and enters the next cycle. The refrigerant entering the compressor must be gas, otherwise, the liquid entering the compressor will be gasified and expanded violently at high temperature, the space of the compression chamber is small, the pressure in the chamber will increase sharply in a short time, and the compression chamber of the compressor will explode, which is also called as "liquid hammer". Therefore, measures must be taken to sufficiently separate the gas and the liquid in the heat exchanger. The common measure is to add a gas-liquid separator, but this will increase the number of equipments, increase the occupied area of equipments, increase the pipeline valve, and also increase the construction investment.

Application No. 201821226626.4 discloses a coiled tube heat exchanger and a refrigeration device having the same. The heat exchanger comprises a shell, a center barrel, heat exchange tubes and a wrapping barrel, wherein the center barrel is fixed in the shell, the heat exchange tubes are wound outside the center barrel, adjacent heat exchange tubes in the same layer of heat exchange tubes are fixed through separation strips, and pad strips are arranged between the adjacent two layers of heat exchange tubes for separation. The structure of the heat exchanger is relatively compact, but the central cylinder occupies the space of the shell, so that the space utilization rate of the shell is low. In addition, as the filler strip is arranged between the two adjacent layers of heat exchange tubes, the restraint of the heat exchange tubes is increased, and the influence of the thermal stress of the heat exchange tubes cannot be eliminated. In addition, the heat exchanger is a pressure container, as is well known, the detection method of the butt welding seam in the field of the pressure container can only select recordable and traceable ray detection or diffraction time difference method ultrasonic detection, the heat exchanger structure disclosed by the patent can not perform ray detection on the welding joint with one end socket connected with the shell, and the use range of the diffraction time difference method ultrasonic detection limits the material and the thickness, so that the feasibility of the safety quality detection of equipment is poor. The design can not complete the full separation of gas and liquid, and a gas-liquid separator is additionally arranged, otherwise, the risk of liquid impact of the compressor is very high.

Disclosure of Invention

The invention provides an evaporator, a manufacturing method of the evaporator and a refrigeration system with the evaporator, aiming at the problems that in the prior art, the gas-liquid separation of the evaporator is insufficient and the safety and the quality of equipment cannot be guaranteed.

In order to achieve the technical purpose, the technical scheme adopted by the invention is as follows:

in a first aspect the present application provides an evaporator comprising:

the upper end and the lower end of the tubular shell are respectively sealed by an upper sealing head and a lower sealing head, wherein the upper sealing head is provided with a first pipe orifice and an air outlet pipe, the lower sealing head is provided with a second pipe orifice, the side surface of the upper end of the tubular shell is provided with a refrigerant outlet, and the side surface of the lower end of the tubular shell is provided with a refrigerant inlet;

an upper sealing plate is arranged between the tubular shell and the upper end enclosure, a lower sealing plate is arranged between the tubular shell and the lower end enclosure, and the upper sealing plate, the tubular shell and the lower sealing plate are sealed to form a heat exchange cavity;

the central column is axially arranged in the cavity, and the upper end and the lower end of the central column are connected to the upper sealing plate and the lower sealing plate;

the multilayer spiral pipes are arranged independently and have the same lead and different diameters, the rotating directions of the two adjacent layers of spiral pipes are opposite, and the upper end and the lower end of each spiral pipe axially extend through the upper sealing plate and the lower sealing plate;

the buffer chamber is arranged in the upper end enclosure, the opening of the buffer chamber is downward and fixed on the upper sealing plate, a plurality of through holes which are distributed in an annular mode are formed in the upper sealing plate positioned outside the buffer chamber, the total flow area of the through holes is larger than that of the air outlet pipe, and the top of the buffer chamber is communicated with the upper pipe opening through the liquid outlet pipe;

the side surface of the lower end of the tubular shell is provided with a first refrigerant inlet, and the first refrigerant inlet is communicated with a liquid distributor surrounding the periphery of the central column.

Adopt above-mentioned technical scheme's evaporimeter, can send into the secondary refrigerant from the low mouth of pipe, flow from the top mouth of pipe behind the multilayer spiral pipe, and refrigerant liquid gets into the back from the first refrigerant import in below, earlier through the heat evaporation of absorbing secondary refrigerant in the spiral pipe, at the in-process that refrigerant gas rises, constantly take place heat exchange with the secondary refrigerant in the spiral pipe, improve the gaseous quality of refrigerant gradually, then get into in the upper cover through the through-hole, discharge from the outlet duct at last, because the radius difference of every layer of spiral pipe and mutually independent again, therefore the heat transfer area of two routes of greatly increased, and just there is not friction between the adjacent two-layer spiral pipe, prevent to damage because of the friction, influence with thermal stress falls to minimum level.

Preferably, the central column is a braided column body formed by processing at least three tubes. The common central column has larger diameter and correspondingly extrudes the inner space in order to meet the pressure-resistant requirement, but the central column formed by twisting or manufacturing the three tube bodies into the braided column body can only occupy a small space, the stress of the braided column body is decomposed into the axial direction, the radial direction, the tangential direction and the like, the axial bearing capacity is higher, and the thermal stress resistance is stronger.

Preferably, the inner surface of the pipe body of each layer of spiral pipe is provided with a plurality of annular bulges which are distributed at equal intervals along the axial direction of the pipe body, and the outer surface of the pipe body of each layer of spiral pipe is densely provided with salient points and grooves with consistent geometric dimension. The annular protrusion can increase the disturbance of fluid in the spiral tube, and is favorable for improving the heat transfer coefficient of the fluid in the tube, and the rough surface of the heat exchange tube, on which the salient points and the pits are densely distributed, is favorable for heat exchange.

Preferably, the outer diameter D1 of the lower closure plate, the largest diameter D2 in the multi-layer spiral tube, and the outer diameter D3 of the upper closure plate satisfy: d1 < D2 < D3. Because the spiral pipe is the structure that the middle section diameter is great, both ends diameter is less, consequently can design the tubular casing into the lower extreme diameter less, the great shape of upper end diameter, so both reduced the material consumption of tubular casing, also reduced the material consumption of lower shrouding, leave great gas phase space in the upper head at upper shrouding top simultaneously, be convenient for carry out gas-liquid separation.

Preferably, the upper end enclosure is provided with a gas-liquid separation device, and a liquid outlet pipe positioned below the gas-liquid separation device is an expansion corrugated pipe. The gas-liquid separation device is favorable for fully separating gas from liquid of the refrigerant entering the upper end enclosure, dry refrigerant gas is absorbed by the compressor, the operation safety of the compressor is ensured, and meanwhile, the liquid outlet pipe below the gas-liquid separation device is arranged as an expansion corrugated pipe, so that the temperature difference displacement of the liquid outlet pipe can be compensated.

In a second aspect, the present invention provides a method for manufacturing an evaporator, comprising the steps of:

(1) center post processing:

welding and fixing one end of at least three pipe bodies to be processed into a central column with an upper sealing plate or a lower sealing plate, processing the at least three pipe bodies into a braided structure to form the central column, and fixing the central column by using an auxiliary tool;

performing pressure test on each pipe body of the central column, and welding and fixing the other ends of at least three pipe bodies after the pressure tests are qualified;

(2) processing a spiral pipe:

processing each layer of spiral pipe layer by layer from the inner layer to the outer layer, wherein the spiral pipes are arranged on the outer side of the central column and are mutually independent, each layer of spiral pipe has the same lead and different diameters, the rotating directions of the two adjacent layers of spiral pipes are opposite, the upper end head and the lower end head of each spiral pipe axially extend through the upper sealing plate and the lower sealing plate, and the spiral pipes, the upper sealing plate and the lower sealing plate are fixed in a spot welding manner;

carrying out ball passing test and pressure test on the spiral pipe, cutting off the redundant pipe body beyond the upper sealing plate and the lower sealing plate after the test is qualified, and welding and fixing the upper end and the lower end of the spiral pipe with the upper sealing plate and the lower sealing plate;

(3) processing the tubular shell:

a liquid distributor surrounds the periphery of the lower end of the central column and is fixed on the upper part of the lower sealing plate, and an inlet of the liquid distributor is connected with a first refrigerant inlet;

welding the tubular shell between the upper sealing plate and the lower sealing plate in a fillet weld mode, adjusting the position of a first refrigerant inlet, sealing through holes in the upper sealing plate by using a temporary tool, then performing pressure test on the whole formed by the upper sealing plate, the lower sealing plate and the tubular shell, removing the temporary tool after the test is qualified, finally welding a buffer chamber on the upper sealing plate in the fillet weld mode, welding an upper end socket on the upper sealing plate at the periphery of the buffer chamber in the fillet weld mode, and welding a lower end socket at the bottom edge of the lower sealing plate in the fillet weld mode.

By adopting the manufacturing method of the technical scheme, the working safety of the evaporator can be ensured in the whole process, and on the premise of meeting the strength design requirement according to the specification of the design standard of the pressure container, the fillet weld mode is adopted to weld the welding joints of the tubular shell, the upper sealing plate, the lower sealing plate and the upper sealing head, so that the ray detection is not needed, the processing difficulty is reduced, and the detection cost is also reduced.

Preferably, for the place where the spiral pipe is spliced, the weld joint margin at the outer surface splicing position needs to be polished to be flush with the base material, softening heat treatment is carried out on the two sides of the welding joint position within the range of at least 30mm, and finally 100% ray detection is carried out on the splicing joint.

The invention provides a refrigeration system in a third aspect, which comprises a refrigeration compressor, an oil separator, a condenser, a liquid receiver, a spiral tube evaporator, a buffer tank, a conveying device and a secondary refrigerant heat exchange room;

the spiral tube evaporator adopts the evaporator as claimed in any one of claims 1 to 5, wherein a second refrigerant inlet is arranged on the side surface of the upper end of the tubular shell, an independent coil surrounding the periphery of the central column is communicated with the second refrigerant inlet, and an outlet of the independent coil penetrates out of the side surface of the upper end of the tubular shell and returns to the first refrigerant inlet through a throttle valve;

the refrigeration compressor, the condenser and the liquid receiver are sequentially communicated, the outlet of the liquid receiver is communicated with the second refrigerant inlet of the spiral tube evaporator, and the air outlet pipe of the spiral tube evaporator is communicated with the inlet of the refrigeration compressor to form refrigeration cycle;

the secondary refrigerant flowing out of the upper pipe orifice of the spiral pipe evaporator is cached in the buffer tank, the outlet of the buffer tank is communicated with the conveying device, the conveying device conveys the secondary refrigerant to the secondary refrigerant heat exchange room to be heated to the required temperature, and then the secondary refrigerant is conveyed to the lower pipe orifice of the spiral pipe evaporator.

Preferably, the spiral tube evaporator is provided with a liquid level sensing device, a control valve is arranged at the front section of the throttling valve, the control valve is electrically connected with the liquid level sensing device, and the control valve is adjusted through liquid level data of the spiral tube evaporator detected by the liquid level sensing device.

Preferably, the side surface of the lower end of the tubular shell and the refrigeration compressor are also provided with an oil discharge pipe, and the oil discharge pipe is provided with a regulating valve.

By adopting the technical scheme, the refrigeration system utilizes the multilayer spiral pipe structure of the evaporator to improve the heat exchange effect, and can also complete gas-liquid separation, so that a gas-liquid separator is not required to be independently arranged, the system is simpler, the floor area of equipment is reduced, the number of the equipment and pipeline valves is reduced, and the construction investment is reduced.

Drawings

FIG. 1 is a schematic view of an evaporator according to embodiment 1 of the present application;

FIG. 2 is a cross-sectional view of a spiral pipe in embodiment 1 of the present application

Fig. 3 is a top view of the upper sealing plate in example 1 of the present application;

FIG. 4 is a schematic view of an evaporator according to embodiment 2 of the present application;

FIG. 5 is a schematic view of an evaporator according to embodiment 3 of the present application;

fig. 6 is a schematic structural diagram of a refrigeration system according to the present application.

The notation in the figure is:

51-tubular shell, 511-first refrigerant inlet, 512-liquid distributor, 513-second refrigerant inlet, 52-upper sealing plate, 521-through hole, 53-lower sealing plate, 54-heat exchange chamber, 541-independent coil, 55-upper end enclosure, 551-upper pipe orifice, 552-air outlet pipe, 553-liquid outlet pipe, 554-gas-liquid separation device, 56-lower end enclosure, 561-lower pipe orifice, 57-central column, 58-spiral pipe, 581-annular bulge, 59-gas-liquid separation chamber and 591-buffer chamber;

1-refrigeration compressor, 2-oil separator, 3-condenser, 4-liquid receiver, 5-spiral tube evaporator, 514-control valve, 515-liquid level sensing device, 516-throttling valve, 517-liquid level display device, 6-buffer tank, 7-conveying device, 71-front stop valve, 72-filter, 73-pump, 74-check valve, 75-rear stop valve, 8-refrigerating medium heat exchange chamber and 9-regulating valve.

Detailed Description

In order to facilitate understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.

Example 1:

as shown in fig. 1-3, an evaporator comprises a tubular housing 51, an upper sealing plate 52, a lower sealing plate 53, an upper head 55, and a lower head 56, wherein the tubular housing 51 is arranged vertically, the upper and lower ends are sealed by the upper head 55 and the lower head 56, respectively, an upper nozzle 551 and an air outlet pipe 552 are arranged on the upper head 55, and a lower nozzle 561 is arranged on the lower head 56.

An upper sealing plate 52 is arranged between the tubular shell 51 and the upper sealing head 55, a lower sealing plate 53 is arranged between the tubular shell 51 and the lower sealing head 56, a gas-liquid separation chamber 59 is formed between the upper sealing head 55 and the upper sealing plate 52, the tubular shell 51 and the lower sealing plate 53 surround to form a heat exchange chamber 54.

A central column 57 is provided for supporting the heat exchange chamber 54 in the axial direction, i.e., at the center of the upper and

lower seal plates

52 and 53.

The multilayer spiral pipes 58 are arranged around the central column 57, the multilayer spiral pipes 58 all take the central column 57 as an axis, each layer of spiral pipes 58 are independently arranged and have the same lead and different diameters, the different diameters refer to that the diameters of the spiral pipes 58 in each layer are different, but the spiral diameters of the main parts of the same spiral pipe 58 from top to bottom except for two ends are the same, namely, the spiral pipe 58 is actually a cylindrical spiral pipe.

In the case of the three-layer spiral pipe 58 in the present embodiment, the diameter of the inner-layer spiral pipe 58 is smallest, the diameter of the middle-layer spiral pipe 58 is second, and the diameter of the outer-layer spiral pipe 58 is larger. The lead, i.e., the pitch of the helical tube 58, represents the distance the helical tube moves axially in one revolution.

The rotating directions of the two adjacent layers of spiral tubes 58 are opposite, the rotating directions of the spiral tubes 58 are left-handed and right-handed, the rotating direction accords with the right-handed four-finger holding rotating direction, the moving point ascends along the direction of the thumb and is called a right spiral line, the rotating direction accords with the left-handed four-finger holding rotating direction, and the moving point descends along the direction of the thumb and is called a left spiral line. In this embodiment, the three-layer spiral tube 58 may be distributed in a left-handed-right-handed or right-handed-left-handed-right-handed manner.

The upper and lower ends of the coil 58 converge towards the central post 57 (but do not touch, and the inner coil 58 is closer than the outer coil 58) and then extend axially past the upper and

lower closure plates

52, 53. Specifically, in the final evaporator, the upper and lower ends of the coil 58 are flush with the upper and

lower closure plates

52, 53.

The upper sealing plate 52 in the gas-liquid separation chamber 59 is provided with a dome-shaped buffer chamber 591, the central axis of the buffer chamber 591 coincides with the axis of the upper sealing plate 52, the opening of the buffer chamber 591 faces downwards, the opening of the buffer chamber 591 is fixed on the upper sealing plate 52 along the welding direction, the radius of the buffer chamber 591 is smaller than that of the upper sealing plate 52, an annular gap is ensured to be reserved on the upper sealing plate 52 outside the buffer chamber 591, a plurality of through holes distributed in an annular shape are formed in the annular gap, so that gas in the heat exchange chamber 54 can enter the gas-liquid separation chamber 59, the total flow area of the plurality of through holes is larger than that of the gas outlet pipe 552, and preferably, the total flow area of the plurality of through holes is larger than twice that of the gas outlet pipe 552.

The top of the buffer chamber 591 is in communication with the upper nozzle 551 via outlet 553, such that coolant entering the coil 58 from the lower nozzle 561 can flow from the outlet 553 to the upper nozzle 551 after entering the buffer chamber 591. While the coolant in the buffer chamber 591 can continue to provide heat with the coolant gas in the gas-liquid separation chamber 59.

The lower end side of the tubular housing 51 is provided with a first refrigerant inlet 511, and a liquid distributor 512 surrounding the outer periphery of the center pillar 57 is communicated with the first refrigerant inlet 511.

The liquid distributor 512 is provided to prevent the liquid entering the heat exchange chamber 54 from the refrigerant inlet from directly washing the spiral tube 58, and the liquid distributor 512 can be replaced by a liquid baffle simply to prevent the liquid from impacting the spiral tube 58, thereby ensuring the heat exchange effect.

In the prior art, for example, the patent document of application No. 201821226626.4 uses a cylindrical tube with a large diameter to support, which extrudes the inner space, the central column 57 in this application uses a braided column body formed by at least three tubes, which only occupies a small space, and the force applied to the braided column body is decomposed into axial, radial, tangential and other directions, so that the axial bearing capacity is high, and the thermal stress resistance is also strong.

Of course, besides the plait-shaped column body, a plurality of tube bodies can also be twisted.

As shown in fig. 2, a plurality of annular protrusions 581 are arranged on the inner surface of the tube body of each layer of spiral tubes 58 at equal intervals along the axial direction of the tube body, and the outer surface of the tube body of each layer of spiral tubes 58 is densely distributed with protrusions and grooves with consistent geometric dimensions. The annular protrusion 581 can increase the disturbance of the fluid in the spiral tube 58, which is beneficial to improving the heat transfer coefficient of the fluid in the tube, and the rough surface of the spiral tube 58 with dense salient points and pits is beneficial to heat exchange.

Assuming that the outer diameter of the lower closure plate 53 is D1, the maximum diameter of the multi-layer spiral tube 58 is D2, and the outer diameter of the upper closure plate 52 is D3, D1, D2, and D3 preferably satisfy: d1 < D2 < D3, so that the evaporator can form a structure with a large upper part and a small lower part, and because two ends of the multi-layer spiral pipe 58 are inwards contracted, the spiral pipe 58 is of a structure with a large middle section diameter and small two end diameters, so that the tubular shell 51 can be designed into a shape with a small lower end diameter and a large upper end diameter, thereby reducing the material consumption of the tubular shell 51 and the lower sealing plate 53, and simultaneously reserving a large gas phase space in the upper sealing head 55 at the top of the upper sealing plate 52, and facilitating gas-liquid separation.

Since the diameter of the tubular shell 51 is larger than the maximum diameter D2 of the multi-layer spiral pipe 58 and the maximum diameter D2 of the multi-layer spiral pipe 58 is larger than the diameter of the lower sealing plate 53, the diameter of the tubular shell 51 is inevitably larger than the diameter of the lower sealing plate 53, so that the tubular shell 51 and the lower sealing plate 53 can be connected and transited by using a conical shell.

In order to prevent the liquid outlet pipe 553 in the gas-liquid separation chamber 59 from being displaced by a temperature difference, at least a part of the liquid outlet pipe 553 in the gas-liquid separation chamber 59 is provided as an expansion bellows.

Example 2:

as shown in fig. 4, the present embodiment is different from embodiment 1 in that a horizontally-arranged gas-liquid separating device 554 is provided in the gas-liquid separating chamber 59 of the upper head 55, so that the refrigerant gas located below the gas-liquid separating device 554 can be sufficiently separated into gas and liquid after passing through the gas-liquid separating device 554, and the dry refrigerant gas after gas-liquid separation flows out from the gas outlet pipe 552.

In this case, the gas-liquid separation chamber 59 provided with the gas-liquid separator 554 may be provided with only an expansion bellows in a part of the liquid outlet pipe 553 positioned below the gas-liquid separator 554.

Example 3:

as shown in fig. 5, the difference from embodiment 1 is that in this embodiment, a second refrigerant inlet 513 is formed on the upper end side surface of the tubular housing 51, an independent coil 541 surrounding the periphery of the central column 57 is disposed at the upper portion of the heat exchange chamber 54, the inlet of the independent coil 541 is communicated with the second refrigerant inlet 513, the outlet of the independent coil 541 penetrates out from the upper end side surface of the tubular housing 51, and enters the heat exchange chamber 54 again from the first refrigerant inlet 511 through a throttle 516.

The working principle is as follows: the secondary refrigerant is fed from the lower pipe opening 561, flows out from the upper pipe opening 551 after passing through the multilayer spiral pipe 58, the refrigerant liquid firstly enters the independent coil 541 from the second refrigerant inlet 513 at the upper part to absorb the external cold, is subcooled and then enters the liquid distributor 512 from the first refrigerant inlet 511 at the lower part through the throttle valve 516, absorbs the heat of the secondary refrigerant in the spiral pipe 58 and then is evaporated, the evaporated refrigerant flows upwards to exchange heat with the refrigerant liquid in the independent coil, finally enters the gas-liquid separation chamber 59 from the through hole, completes the gas-liquid separation in the gas-liquid separation chamber 59 and then is discharged from the gas outlet pipe 552.

Because the evaporator of this application belongs to pressure vessel, but the detection method of the butt weld in the present pressure vessel field can only adopt recordable, traceable ray detection or diffraction time difference method ultrasonic testing, and this all has the restriction to material and thickness, consequently is relatively poor to the detection feasibility of equipment quality.

Example 4:

for the evaporator described in embodiment 1, this embodiment provides a corresponding manufacturing method, which specifically includes the following steps:

s1: center post processing:

and one end of each of the three pipe bodies to be processed into the central column is welded and fixed with the upper sealing plate, and the three pipe bodies are processed into a braided structure to form the central column and are fixed by the auxiliary tool.

And performing pressure test on each pipe body of the central column, and welding and fixing the other ends of the three pipe bodies and the lower sealing plate after the pressure tests are all qualified.

The number of the tube bodies of the central column can be determined according to the supporting strength of the evaporator, generally no less than 3 tube bodies can form a braid-shaped structure, and of course, a plurality of tube bodies can also form the central column in a twisting mode.

It should be noted that, this application is earlier welded fastening body one end and last shrouding, treats that pressure test is qualified after, the welded fastening body other end and lower shrouding again, and it is also right to reverse, also promptly welds fastening body one end and lower shrouding earlier, treats that pressure test is qualified after, the welded fastening body other end and last shrouding again, and two kinds of processing methods effects are the same.

When the central post is vertically arranged, the upper end and the lower end of the central post are preferably arranged at the centers of the upper sealing plate and the lower sealing plate.

S2: processing a spiral pipe:

in the center post periphery, from the inlayer to each layer of spiral pipe of outer successive layer processing, the spiral pipe is arranged in the center post outside and mutually independent, and each layer of spiral pipe has the same helical pitch (pitch) and different diameter, and the revolving of adjacent two-layer spiral pipe is opposite, and both ends head is drawn close the back to the center post about the spiral pipe and is passed last shrouding and shrouding down along the axial to it is fixed with spiral pipe and last shrouding and shrouding down to carry out spot welding.

It should be noted that, the upper and lower ends of the spiral pipe need to penetrate at least 100mm through the upper and lower sealing plates.

And then carrying out ball passing test and pressure test on the spiral pipe, cutting off the redundant pipe body exceeding the upper sealing plate and the lower sealing plate after the test is qualified, and finally welding and fixing the upper end head and the lower end head of the spiral pipe with the upper sealing plate and the lower sealing plate.

For the place that the spiral pipe has the concatenation, need polish the welding seam surplus height of surface concatenation department as to the base metal flush, carry out softening heat treatment with the at least 30mm scope in welded joint position both sides, because the rigidity of concatenation department takes place the sudden change greatly when preventing to process the spiral pipe, carry out 100% ray detection to the concatenation joint at last, make it accord with NB/T47013.2's II level requirement.

In the embodiment, the ball passing test requires that the ball passing test is carried out by using small balls (steel balls, rubber balls, iron balls or wood balls) with the inner diameter of the spiral pipe being not less than 85 percent, and the steel balls pass through the spiral pipe smoothly as qualified.

It is particularly noted that when the spiral pipe is assembled from the inner layer to the outer layer, the inner layer is required to be processed and the outer layer spiral pipe is required to be processed after the inner layer is qualified through ray detection (if required), a ball passing test and a pressure test.

S3: processing the tubular shell and the upper and lower end sockets:

the liquid distributor surrounds the periphery of the lower end of the central column and is fixed on the upper part of the lower sealing plate, and an inlet of the liquid distributor is connected with a first refrigerant inlet;

The welding joints of the tubular shell, the upper sealing plate, the lower sealing plate and the upper sealing head and the lower sealing head are welded in a fillet welding mode, so that ray detection is not needed, the processing difficulty is reduced, and the detection cost is also reduced.

Based on the advantages of the evaporator, the invention also provides a refrigeration system which comprises a refrigeration compressor 1, an oil separator 2, a condenser 3, a liquid receiver 4, a spiral tube evaporator 5, a buffer tank 6, a conveying device 7 and a refrigerating medium heat exchange room 8, as shown in fig. 6.

The spiral-tube evaporator 5 specifically adopts the evaporator structure in embodiment 3, that is, a second refrigerant inlet 513 is arranged on the upper end side of the tubular housing 51, a separate coil 541 surrounding the periphery of the center post 57 is communicated with the second refrigerant inlet 513, and the outlet of the separate coil 541 passes through the upper end side of the tubular housing 51 and returns to the first refrigerant inlet 511 through the throttle valve 516.

The refrigeration compressor 1, the condenser 3 and the liquid receiver 4 are sequentially communicated, the outlet of the liquid receiver 4 is communicated with the second refrigerant inlet 513 of the spiral tube evaporator 5, and the air outlet pipe 552 of the spiral tube evaporator 5 is communicated with the inlet of the refrigeration compressor 1 to enter the next refrigeration cycle. If the condenser 3 has a liquid storage space at the bottom, the liquid receiver 4 may not be used, but the outlet of the condenser 3 is directly connected to the second refrigerant inlet 513 of the coil evaporator 5.

The secondary refrigerant flowing out of the upper pipe opening 551 of the spiral pipe evaporator 5 is cached in the buffer tank 6, the outlet of the buffer tank 6 is communicated with the conveying device 7, the conveying device 7 sends the secondary refrigerant to the secondary refrigerant heat exchange room 8 to be heated to the required temperature, and then sends the secondary refrigerant with the specific temperature to the lower pipe opening 561 of the spiral pipe evaporator 5.

Of course, in order to improve the automatic control effect, the coil evaporator 5 is provided with a liquid level sensing device 515, a control valve 514 is arranged at the front section of the throttle valve 516, the control valve 514 is electrically connected with the liquid level sensing device 515, when the liquid level sensing device 515 detects that the liquid level of the coil evaporator 5 is low, the flow rate of the refrigerant is improved by sending a signal to the control valve 514, so that the liquid level height of the coil evaporator 5 is increased; similarly, when the level sensing device 515 detects that the liquid level in the coil evaporator 5 is high, the refrigerant flow is reduced by sending a signal to the control valve 514, thereby causing the liquid level in the coil evaporator 5 to gradually decrease.

The side of the spiral tube evaporator 5 is provided with a liquid level display device 517, so that the real-time liquid level condition of the spiral tube evaporator 5 can be conveniently and visually observed.

In order to facilitate the oil return operation of the coil evaporator 5, an oil drain pipe is provided between the lower end side of the tubular housing 51 and the refrigeration compressor 1, and the oil drain pipe is provided with a regulating valve 9 for controlling the oil return flow.

The working principle of the refrigeration system is briefly described below:

the refrigeration compressor 1 sucks in low-temperature and low-pressure refrigerant gas, discharges high-temperature and high-pressure superheated refrigerant gas after compression, separates and removes lubricating oil in the refrigerant gas in the oil separator 2, then the refrigerant gas enters the condenser 3 to be condensed into high-temperature and high-pressure saturated (or with a certain supercooling degree) refrigerant liquid, the refrigerant liquid enters the liquid receiver 4 and then enters the independent coil 541 at the upper part of the heat exchange chamber 54 through the second refrigerant inlet 513 to absorb the cold energy of the external low-temperature refrigerant gas, the refrigerant liquid is supercooled (or continuously cooled), is throttled and depressurized through the throttle valve 516, the throttled and depressurized low-temperature and low-pressure refrigerant liquid enters the liquid distributor 512 at the lower part of the heat exchange chamber 54 from the first refrigerant inlet 511 at the bottom of the coil evaporator 5, so as to absorb the heat of the refrigerant in the coil 58 and then evaporate, and the evaporated refrigerant gas continuously absorbs the heat of the refrigerant in the coil 58 during the rising process, the refrigerant gas with liquid drops passes through the through hole 521 to enter the gas-liquid separation chamber 59, gas-liquid separation is completed in the gas-liquid separation chamber 59, and the saturated refrigerant gas is sucked away by the refrigeration compressor 1 to enter the next refrigeration cycle.

When the coil evaporator 5 needs oil return operation, the control valve 514 closes the refrigerant liquid supply port of the coil evaporator 5, after the liquid refrigerant in the coil evaporator 5 is completely gasified and sucked away by the refrigeration compressor 1, the lubricating oil is deposited at the bottom of the heat exchange chamber 54, at this time, the air outlet valve of the control air outlet pipe 552 is closed, the regulating valve 9 on the oil drain pipe is slightly opened, the regulating valve 9 has throttling function, and the lubricating oil is slowly sucked back into the refrigeration compressor 1.

The secondary refrigerant from the secondary refrigerant heat exchange room 8 enters the spiral pipe 58 from the lower nozzle 561 at the bottom of the spiral pipe evaporator 5, and after heat exchange with the refrigerant outside the spiral pipe 58, the temperature of the secondary refrigerant is reduced, and then the secondary refrigerant flows out from the top of the spiral pipe evaporator 5, is temporarily stored in the buffer tank 6 and then is sent to the conveying device 7. The conveying device 7 is divided into two paths, each path is respectively provided with a front stop valve 7171, a filter 7272, a pump 7373, a check valve 7474 and a rear stop valve 7575, one path works normally, and the other path is standby. During normal operation, the front stop valve 7171 and the rear stop valve 7575 are both opened, one pump 7373 is opened, if the pump 7373 breaks down, the other pump 7373 can be immediately switched on, the switching process can be set to be automatically completed, then the front stop valve 7171 and the rear stop valve 7575 of the pump 7373 are closed, and the pump 7373 is repaired.

The secondary refrigerant from the conveying device 7 is conveyed to the secondary refrigerant heat exchange room 8 capable of heating the secondary refrigerant to different temperatures, so that the secondary refrigerants with different temperatures are provided for the secondary refrigerant heat exchangers, a refrigeration cycle is shared on the basis of providing the secondary refrigerants with various temperatures, an evaporator is shared, the number of machines, equipment, pipelines and valves in the system is reduced, the system is simpler, and the operation and the management are more convenient.

After the heat exchange is carried out by the secondary refrigerant heat exchange room 8, the temperature of the secondary refrigerant is increased, and the secondary refrigerant enters the spiral pipe 58 from the bottom of the secondary refrigerant heat exchanger to be cooled again and then is circulated for the next time.

The evaporator, the manufacturing method of the evaporator and the refrigeration system with the evaporator provided by the application are described in detail above. The description of the specific embodiments is only intended to facilitate an understanding of the methods of the present application and their core concepts. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present application without departing from the principle of the present application, and such improvements and modifications also fall within the scope of the claims of the present application.

Claims

1. An evaporator, comprising:

the upper end and the lower end of the tubular shell (51) are respectively sealed by an upper sealing head (55) and a lower sealing head (56), wherein the upper sealing head (55) is provided with a first pipe orifice and an air outlet pipe (552), the lower sealing head (56) is provided with a second pipe orifice, the side surface of the upper end of the tubular shell (51) is provided with a refrigerant outlet, and the side surface of the lower end is provided with a refrigerant inlet;

an upper sealing plate (52) is arranged between the tubular shell (51) and the upper sealing head (55), a lower sealing plate (53) is arranged between the tubular shell (51) and the lower sealing head (56), and the upper sealing plate (52), the tubular shell (51) and the lower sealing plate (53) are sealed to form a heat exchange cavity (54);

the central column (57) is axially arranged in the cavity, and the upper end and the lower end of the central column (57) are connected to the upper sealing plate (52) and the lower sealing plate (53);

the multilayer spiral pipes (58) surround the outer side of the central column (57), the multilayer spiral pipes (58) are independently arranged and have the same lead and different diameters, the rotating directions of the two adjacent layers of spiral pipes (58) are opposite, and the upper end and the lower end of each spiral pipe (58) axially extend through the upper sealing plate (52) and the lower sealing plate (53);

the buffer chamber (591) is arranged in the upper sealing head (55) and is fixed on the upper sealing plate (52) with a downward opening, wherein a plurality of through holes (521) are annularly distributed on the upper sealing plate (52) positioned outside the buffer chamber (591), the total flow area of the through holes (521) is larger than that of the air outlet pipe (552), and the top of the buffer chamber (591) is communicated with the upper pipe orifice (551) through the liquid outlet pipe (553);

the side surface of the lower end of the tubular shell (51) is provided with a first refrigerant inlet (511), and a liquid distributor (512) surrounding the periphery of the central column (57) is communicated with the first refrigerant inlet (511).

2. An evaporator according to claim 1 wherein the central column (57) is a braided cylinder formed from at least three tubes.

3. An evaporator according to claim 2 wherein the inner surface of the tube body of each of the spiral tubes (58) is provided with a plurality of annular protrusions (581) equally spaced along the axial direction of the tube body, and the outer surface of the tube body of each of the spiral tubes (58) is densely provided with protrusions and grooves of uniform geometrical dimensions.

4. An evaporator according to claim 1 wherein the outer diameter D1 of the lower closure plate (53), the largest diameter D2 of the multi-layer coil (58) and the outer diameter D3 of the upper closure plate (52) are such that: d1 < D2 < D3.

5. An evaporator according to claim 1, characterized in that the upper head (55) is provided with a gas-liquid separation device (554), and a liquid outlet pipe (553) below the gas-liquid separation device (554) is provided as an expansion bellows.

6. A method of manufacturing an evaporator, comprising the steps of:

(1) center post processing:

(2) processing a spiral pipe:

(3) processing the tubular shell:

7. The method as claimed in claim 6, wherein for the place where the spiral pipe is spliced, the weld bead height of the outer surface splicing part is ground to be flush with the base material, the softening heat treatment is performed within a range of at least 30mm on both sides of the welding joint position, and finally the 100% ray inspection is performed on the splicing joint.

8. The refrigeration system is characterized by comprising a refrigeration compressor (1), an oil separator (2), a condenser (3), a liquid receiver (4), a spiral tube evaporator (5), a buffer tank (6), a conveying device (7) and a refrigerating medium heat exchange room (8);

the spiral-tube evaporator (5) adopts the evaporator as claimed in any one of claims 1 to 5, wherein a second refrigerant inlet (513) is arranged on the side surface of the upper end of the tubular shell (51), an independent coil (541) surrounding the periphery of the central column (57) is communicated with the second refrigerant inlet (513), and the outlet of the independent coil (541) penetrates out of the side surface of the upper end of the tubular shell (51) and returns to the first refrigerant inlet (511) through the throttle valve (516);

the refrigeration compressor (1), the condenser (3) and the liquid receiver (4) are sequentially communicated, the outlet of the liquid receiver (4) is communicated with a second refrigerant inlet (513) of the spiral tube evaporator (5), and an air outlet pipe (552) of the spiral tube evaporator (5) is communicated with the inlet of the refrigeration compressor (1) to form refrigeration cycle;

the secondary refrigerant flowing out of an upper pipe opening (551) of the spiral pipe evaporator (5) is cached in a buffer tank (6), an outlet of the buffer tank (6) is communicated with a conveying device (7), the conveying device (7) conveys the secondary refrigerant to a secondary refrigerant heat exchange room (8) to be heated to a required temperature, and then the secondary refrigerant is conveyed to a lower pipe opening (561) of the spiral pipe evaporator (5).

9. A refrigeration system as claimed in claim 8, characterized in that the coil evaporator (5) is provided with a liquid level sensor (515), a control valve (514) is provided in front of the throttle valve (516), the control valve (514) is electrically connected to the liquid level sensor (515), and the control valve (514) is adjusted by the liquid level data of the coil evaporator (5) detected by the liquid level sensor (515).

10. Refrigeration system according to claim 9, characterized in that the lower end side of the tubular housing (51) and the refrigeration compressor (1) are further provided with an oil drain, on which the regulating valve (9) is provided.