CN110038313B

CN110038313B - Design method of evaporator inlet pipe and seawater desalination system thereof

Info

Publication number: CN110038313B
Application number: CN201910460606.6A
Authority: CN
Inventors: 郭春生; 李佳航; 赵婉莹; 周磊
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2018-10-29
Filing date: 2018-10-29
Publication date: 2020-10-20
Anticipated expiration: 2038-10-29
Also published as: CN109231320B; CN110038314B; CN110038314A; CN109231320A; CN110038313A

Abstract

The invention provides a design method of an evaporator inlet pipe and a seawater desalination system thereof, wherein the evaporator comprises an inlet collecting pipe, an outlet collecting pipe and a heat exchange part connected between the collecting pipes, the inlet collecting pipe and the outlet collecting pipe are respectively connected with a steam inlet pipe and a condensed water outlet pipe, and the inlet pipe is designed in the following mode: the diameter of the steam inlet pipe increases continuously along the direction of fluid flow. The invention adopts a new inlet pipe design method, can reduce the flow resistance, and enables the vapor evaporated in the vapor inlet pipe to continuously move towards the direction of increasing the pipe diameter, thereby further promoting the circulating flow of the loop heat pipe, and the impact phenomenon caused by the increase of the volume of the vapor outlet can be reduced by the increase of the pipe diameter of the vapor inlet pipe.

Description

Design method of evaporator inlet pipe and seawater desalination system thereof

Technical Field

The invention relates to the field of heat exchangers, in particular to a steady flow evaporator.

Background

The heat pipe technology was Ross Alamos (Los Alamos) in 1963National laboratoryGeorge Grover, a heat transfer called "heat pipe" of the inventionComponentThe heat conduction principle and the rapid heat transfer property of the phase change medium are fully utilized, the heat of a heating object is rapidly transferred to the outside of a heat source through the heat pipe, and the heat conduction capability of the heat pipe exceeds the heat conduction capability of any known metal.

The heat pipe technology is widely applied to the industries of aerospace, military industry and the like, and since the heat pipe technology is introduced into the radiator manufacturing industry, the design idea of the traditional radiator is changed for people, the single heat radiation mode that a high-air-volume motor is used for obtaining a better heat radiation effect is avoided, the heat pipe technology is adopted for enabling the radiator to obtain a satisfactory heat exchange effect, and a new place in the heat radiation industry is opened up. At present, the heat pipe is widely applied to various heat exchange devices, including the fields of solar energy and seawater desalination, such as the utilization of solar energy.

More than 1 ten thousand islands in China, but most of the islands cannot live due to lack of fresh water, and the number of residents is less than 500, so that the functions of island development, national defense and the like are restricted. The implementation scheme of sea water desalination engineering on the island, which is jointly printed by the national development and improvement committee and the national oceanic administration at the end of 2017, provides the method, which effectively relieves the water consumption problem of residents on the island, improves the living environment, enables seawater desalination to be one of main water supply modes in severe water-deficient island areas, and basically meets the continuously-improved requirements on life and production water of the island in 2020.

Aiming at the problems, a desktop-level large-and-small solar seawater desalination system which is based on a phase change enhanced heat transfer mechanism and operates at low temperature and low energy consumption by applying a loop heat pipe technology, a plate CPL capillary pump technology, a novel radiating fin type turbulent flow evaporator and an integrated VC plate fin condenser is provided, a Venturi tube vacuumizing mode is innovatively adopted, equipment is simplified, and energy consumption is greatly reduced. The system adopts a wind-light complementary energy supply system, and is suitable for areas with complex conditions of electric power shortage and fresh water resource shortage. Finally, the upper computer operation platform is connected with the embedded chip control node switch and the acquisition device node sensor data, so that the operation difficulty is remarkably reduced, and unattended operation, remote control and full-automatic operation of equipment are realized.

In view of the above problems, we propose a steady flow evaporator.

Disclosure of Invention

The invention provides a steady flow evaporator which can reduce the water hammer phenomenon caused by space expansion when a steam-water mixture enters an inlet header.

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

a steady flow evaporator comprises an inlet header, an outlet header and a heat exchange component connected between the headers, wherein the inlet header and the outlet header are respectively connected with a steam inlet pipe and a condensed water outlet pipe; the flow stabilizer is composed of a square structure and a regular octagonal structure, so that a square through hole and a regular octagonal through hole are formed, the length of the side of the square through hole is equal to the length of the side of the regular octagonal through hole, the four sides of the square through hole are the sides of four different regular octagonal through holes respectively, and the four mutually spaced sides of the regular eight deformation through holes are the sides of four different square through holes respectively.

Preferably, the evaporator comprises an inlet header connected to the inlet heat exchange tubes, an outlet header connected to the corresponding plate pack, an inlet heat exchange tube, an outlet heat exchange tube and a plate pack, the plate pack is a heat exchange channel formed by combining two plates together, the plate pack is connected to the outlet heat exchange tubes, the outlet heat exchange tubes are connected to the outlet header, and fluid from the evaporation end enters the inlet heat exchange tubes through the inlet header, then enters the plate pack through the inlet heat exchange tubes, then enters the outlet heat exchange tubes through the plate pack, and then is discharged through the outlet header.

A seawater desalination system comprises an evaporation system, a condensation system and a fresh water collection system, wherein seawater is evaporated in the evaporation system to generate steam, the steam is condensed in the condensation system to become fresh water, the fresh water is collected by the fresh water collection system,

the evaporation system comprises the steady flow evaporator described above.

the condensing system comprises the heat exchange device.

Preferably, the seawater desalination system comprises an evaporation system, a condensation system and a fresh water collection system, seawater is evaporated in the evaporation system to generate steam, the steam is condensed in the condensation system to become fresh water, the fresh water is collected by the fresh water collection system,

the evaporation system comprises a solar heat collector and a loop heat pipe, wherein the evaporation end of the loop heat pipe absorbs solar energy and then exchanges heat with seawater at the condensation end to evaporate the seawater;

the fresh water collecting system comprises an upper water receiving tray and a lower water receiving tray, the upper water receiving tray is positioned at the lower part of the condenser and positioned at the upper part of the lower water receiving tray, the middle of the upper water receiving tray is provided with a hole, the end part of the outermost end is provided with an upward vertical part, a horizontal part is connected with the vertical part, and an upward inclined part extends inwards along the horizontal part; the horizontal part is provided with holes for fresh water to flow into the lower water receiving tray; the lower water receiving disc comprises a hole part in the middle, and the hole part is connected with the fresh water collecting box;

the seawater desalination system also comprises a vacuum system, and the condenser, the upper water receiving tray, the lower water receiving tray and the condensing end of the loop heat pipe are arranged in the vacuum system.

The condenser, the upper water receiving tray, the lower water receiving tray and the condensing ends of the loop heat pipes are sequentially arranged from top to bottom.

Preferably, the system also comprises a seawater circulating spraying system, wherein the seawater circulating spraying system is arranged in the vacuum system and comprises a circulating spraying pump, an atomizing spraying head and a circulating pipeline, and the atomizing spraying head is arranged at the upper part of the condensation end; the circulating spray pump pumps the seawater in the vacuum system into the atomizing spray header, and then the seawater is sprayed to the condensation end.

Preferably, the evaporation end is of a plate structure, the solar heat collector comprises a solar heat collecting plate, and the upper surface of the evaporation end is attached to the lower surface of the solar heat collecting plate.

Preferably, the evaporation end is of a plate structure, and the upper surface of the evaporation end is the solar heat collection plate.

Preferably, the vacuum system comprises a vacuum tank, and the condenser, the upper water receiving tray, the lower water receiving tray and the condensing end are arranged in the vacuum tank.

Preferably, a seawater concentration detection device is arranged in the tank body and used for detecting the concentration of seawater, and the controller automatically controls the seawater discharge according to the detected seawater concentration.

Compared with the prior art, the invention has the following advantages:

1) the invention adopts the flow stabilizer with a novel structure, namely the flow stabilizer in the loop heat pipe is subjected to field transfer and is applied to the inlet pipe at the evaporation end of the loop heat pipe, so that the water hammer phenomenon caused by space expansion when a steam-water mixture enters the inlet header is reduced.

2) By arranging the circulating spraying heat exchange system, the invention can utilize the heat of the evaporator absorbed in the unevaporated seawater to convert the seawater into fresh water to the maximum extent, thereby realizing the maximum utilization effect.

3) According to the invention, by arranging the novel fresh water collecting system and arranging the inner and outer water receiving discs, the height of the outer disc is slightly higher than that of the inner disc, the fresh water collecting coverage area can reach the whole vacuum tank interface, and meanwhile, the gap between the inner disc and the outer disc can play a role in drainage. Through above-mentioned structure, the realization fresh water that can be comprehensive is collected, has further improved the ability and the effect of sea water fresh water.

4) The invention provides a novel plate-type condensation heat exchanger, wherein a condensation device consists of five layers of fins, temperature-equalizing plates, cold water channels, temperature-equalizing plates and fins from top to bottom, each layer plays the respective role in the condensation process, and the layered design is convenient to process; the spoilers are inserted between the isolation transverse plates, so that the purpose of flow winding is achieved, the cold seawater introduced into the spoilers is fully contacted with the upper VC plate and the lower VC plate, and the heat exchange efficiency is increased; numerical simulation and experimental study are carried out on the heat exchange structure, and the optimal relational formula is determined.

5) The CPL technology is combined with seawater desalination. According to the phase change heat exchange principle, a CPL capillary pump capable of remotely transferring large heat under small temperature difference is innovatively combined with seawater desalination equipment, and a plate-type design is adopted, so that the heat transfer efficiency is improved by about 4 times compared with the traditional convection heat exchange mode, and the heat transfer efficiency is greatly improved.

5) A condenser and a falling film evaporator with innovative structures. The condenser adopts the design of piece formula structure, combines temperature-uniforming plate and fin, and VC intracavity adheres to sintering network structure, realizes the phase transition heat transfer, makes the heat evenly spread fast in the plane to increase by a wide margin through the fin structure and steam area of contact, improve heat exchange efficiency, increase about 15% heat transfer efficiency than traditional fin structure. In addition, from designing novel fin formula vortex evaporimeter, the parallelly connected range of multiplate structure has increased by a wide margin and has sprayed the area of contact of sea water with the atomizing, has increased 20% heat transfer efficiency through the actual measurement.

6) The venturi tube achieves vacuum pumping of the wastewater. The waste water that derives the condenser is drained to venturi and is derived again, and venturi one end communicates with each other with the main tank body, utilizes the venturi principle to take out the air, maintains the required vacuum of cryogenic distillation, reduces the energy consumption effectively. The condensing part and the vacuumizing part are ingeniously combined in the design, equipment is simplified, additional vacuumizing by a vacuum pump is not needed, the comprehensive use performance of the equipment is improved, and the use energy consumption is obviously reduced.

7) According to the invention, the novel structure flow stabilizing device is adopted, and through the square and the regular octagon, included angles formed by the sides of the square hole and the regular octagon hole are more than or equal to 90 degrees, so that fluid can fully flow through each position of each hole, and the short circuit of fluid flow is avoided or reduced. The two-phase fluid is separated into the liquid phase and the gas phase by the flow stabilizer with the novel structure, the liquid phase is divided into small liquid masses, the gas phase is divided into small bubbles, the backflow of the liquid phase is inhibited, the gas phase is enabled to flow smoothly, the flow stabilizing effect is achieved, and the vibration and noise reduction effects are achieved. Compared with the current stabilizer in the prior art, the current stabilizer further improves the current stabilizing effect and is simple to manufacture.

The invention has wide application prospect.

1) The product greatly reduces energy consumption and has obvious operation cost advantage. The operation energy consumption of the equipment is about 9000 kilojoules per ton, which is about 1/4 of the operation energy consumption of the traditional multistage flash evaporation and multistage distillation modes, the energy-saving advantage is remarkable, and about 42 ten thousand yuan can be saved compared with other seawater desalination modes every year.

2) The equipment occupies only 1.2 square meters, which is one fifth of the existing common seawater desalination device. At present, the seawater desalination equipment on the market mainly takes large and ultra-large equipment producing thousands of tons of fresh water per day as main equipment, and cannot be applied to small-area places such as fishing boats, small islands and the like. And the novel technology is innovatively adopted by the equipment, so that the occupied area is greatly reduced, and the market blank is made up.

3) Uses stable clean energy. China's islands are mainly distributed in south China sea, the region has long illumination time and strong radiation, is suitable for developing and popularizing a solar seawater desalination device, has no pollution by applying solar clean energy, and accords with the national policy and policy of environmental protection.

The invention analyzes the energy-saving and emission-reducing benefits

1) In terms of device energy acquisition. The energy consumed by the small-sized seawater desalination device mainly comes from solar energy, the data shows that the average solar radiation intensity on the earth orbit is 1369W/m2, the standard peak intensity on the sea level is 1kW/m2, the radiation intensity in the areas near the equator such as the south sea island and the like in China is higher, the solar energy resources are very rich, and compared with petroleum resources which are increasingly consumed, the device adopts solar energy to supplement energy, so that the effective utilization of environment-friendly new energy is successfully realized.

2) In the aspects of fresh water production benefit and secondary pollution. The daily output of the fresh water of the device is 120 liters, which is equivalent to 240 bottles of drinking mineral water and can be supplied to about 50 adults for daily drinking, thereby not only saving the trouble of shipping fresh water influenced by weather factors, but also saving about 512 tons of diesel oil every year, reducing the emission of 81000 kiloliters of carbon dioxide and perfectly realizing the effects of energy conservation and emission reduction.

The device can also solve the problem of drinking fresh water of residents around the saltand soda lake, and compared with vehicle transportation fresh water which needs to discharge a large amount of various polluted tail gas all the way, the device can realize zero-emission desalination of the brine and has no secondary pollution, save fuel resources, protect the ecological environment and effectively reduce the emission of harmful gas at the same time.

3) In terms of the efficiency of operation of the device. Compared with the existing convection heat exchange, the CPL capillary pump adopted by the device improves the heat transfer efficiency by about 4 times by utilizing the phase change heat exchange principle from the mechanical structure of the device; the original design of the integrated VC plate fin condenser obviously increases the heat transfer contact surface area, and increases the heat transfer efficiency by 15 percent compared with the traditional fin structure; the novel radiating fin type turbulent flow evaporator is selected, the heat transfer area is greatly increased due to the parallel arrangement, and the heat transfer efficiency is increased by 20%. The increase of the efficiency means the reduction of unit energy consumption, according to effective calculation, the energy consumption per ton water of the device is only 9000KJ, and accounts for 62.5 percent of the energy consumption of a reverse osmosis desalination mode, 20 percent of the energy consumption of a multi-effect distillation desalination mode and 18 percent of the energy consumption of the multi-effect distillation desalination mode under the same condition, so the energy-saving effect is obvious.

5) In terms of the manner in which the device is controlled. From the operation mode, the device is in full-automatic operation and one-key start and stop, the dependence on manual operation is avoided, the device only needs to be maintained once all the year round, the manual energy consumption is greatly reduced, and various unnecessary energy consumption generated for controlling and maintaining the device is saved.

6) The device can obtain the quality of fresh water. The water produced by the device reaches the standard of drinking water after being checked by the Weihai City Bureau of quality. The energy expenditure required for obtaining fresh water is reduced, the obtained fresh water has good water quality, secondary purification is not needed, the cost is saved, and the energy consumption in the water purification process is also saved.

Drawings

FIG. 1 is a schematic structural diagram of a solar seawater desalination system according to the present invention.

Fig. 2 is a view showing the structure of the fresh water condensing apparatus according to the present invention.

FIG. 3 is a bottom view of the vapor plate of FIG. 2.

FIG. 4-1 is a schematic view of the internal structure of the plate condensing unit of FIG. 2;

FIG. 4-2 is a schematic view of the internal structure of the plate condensing unit of FIG. 2;

fig. 5-1 is a structural view of a solar evaporation system.

Fig. 5-2 is a block diagram of a solar power and electric power combined evaporation system.

FIG. 6 is a schematic diagram of the operation of a loop heat pipe.

FIG. 7-1 is a schematic view of a heat pipe evaporator configuration.

FIG. 7-2 is a schematic sectional view of FIG. 7-1.

Fig. 8-1 is a schematic view of the heat pipe condensation end structure.

Fig. 8-2 is a schematic view of the structure of fig. 8 in a different direction.

FIG. 9 is a schematic view of an evacuation configuration;

FIG. 10 is a schematic diagram of a cyclic spray;

FIG. 11 is a schematic diagram of the fresh water collection system;

FIG. 12 is a schematic cross-sectional view of a partitioning device of the present invention;

FIG. 13 is a schematic view of another cross-sectional configuration of the partitioning device of the present invention;

FIG. 14 is a schematic view of the disposition of the spacers of the present invention within the riser;

FIG. 15 is a schematic representation of the cross-sectional view of the disposition of the spacers of the present invention within the riser.

FIG. 16 is a schematic view of a lower water tray structure;

fig. 17 is a schematic view of the structure of the upper water pan.

The reference numbers are as follows: 1, a solar heat collecting plate, 2 loop heat pipes, 3 electric heating plates, 4 cold water inlets, 5 condensers, 6 water receiving discs, 7 spray headers, 8 evaporators, 9 cold water outlets, 10 venturi tubes, 11 waste water outlets and 12 vacuum tanks; 13 fresh water collecting box, 14 flow stabilizer;

21, collecting the steam in an upper cover plate outer wall, 22 steam channels, 23 capillary cores, 24 liquid channels, 25 base outer walls, 26 gaskets and 27;

the condenser comprises an upper fin 51, an upper temperature-equalizing plate 52, a 521 cavity, a 522 capillary structure, a 523 fin, a cold water inlet 53, a cold water outlet 54, a plate type condensation part 55, a 551 isolation transverse plate, a 552 spoiler, a lower temperature-equalizing plate 56 and a lower fin 57;

61 lower water receiving tray, 611 hole part, 62 upper water receiving tray, 621 hole, 622 vertical part, 623 horizontal part, 624 inclined part

81 inlet pipe, 82 inlet header, 83 inlet heat exchange pipes, 84 plate groups, 85 outlet heat exchange pipes, 86 outlet header, 87 outlet pipe, 88 fresh water collecting pipeline, 89 fresh water collecting barrel, 90 part seawater inlet, 91 centrifugal pump and 92 circulating spraying pipeline

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings.

In this document, "/" denotes division and "×", "denotes multiplication, referring to formulas, if not specifically stated.

As shown in fig. 1, the seawater desalination system includes an evaporation system, a condensation system, and a fresh water collection system, where seawater is evaporated in the evaporation system to generate steam, the steam is condensed in the condensation system to become fresh water, and then the fresh water is collected by the fresh water collection system.

The evaporation system comprises a solar heat collector 1 and a loop heat pipe 2, wherein the evaporation end of the loop heat pipe 2 absorbs solar energy and then exchanges heat with seawater at a condensation end 8 to evaporate the seawater;

the condensation system comprises a condenser 5, and the condenser 5 condenses water vapor generated by evaporation of seawater;

the fresh water collecting system comprises a water receiving tray, and the water receiving tray is positioned at the lower part of the condenser 5 and is used for collecting condensed water generated by condensation of the condenser;

the condenser 5, the water pan and the condensing end of the loop heat pipe are arranged from top to bottom in sequence.

Preferably, the condensing system comprises a condenser 5, the condenser 5 comprises a cold water inlet 53, a cold water outlet 54,

temperature equalizing plates

52,56 and a plate type condensing part 55, the plate type condensing part 55 comprises a plurality of parallel isolation transverse plates 551, a cold water flow channel is formed between adjacent isolation transverse plates 551, a spoiler 552 is arranged in the cold water flow channel, and the spoiler 552 is a bent plate, preferably in a V-shaped bent structure. The spoiler 552 is arranged in the cold water flow channel and is at a certain distance from the isolation transverse plate, and the extending direction of the spoiler 552 is parallel to the isolation transverse plate; the temperature equalizing plate comprises an upper temperature equalizing plate 52 and a lower temperature equalizing plate 56, one end of the upper temperature equalizing plate 52 is arranged at the upper part of the plate type condensing part 55, one end of the lower temperature equalizing plate 56 is arranged at the lower part of the plate type condensing part, and the other end of the temperature equalizing plate, which is far away from the plate type condensing part, is provided with a fin 523; a closed cavity 521 is arranged in the temperature-uniforming plate, and a capillary structure 552 is arranged on the inner side of the cavity 521; the wicking structure 552 is disposed around the inner wall of the cavity 521; the cold water inlet 53 and the cold water outlet 54 are respectively arranged on the opposite side parts of the plate-type condensation part;

the VC plates, namely the

uniform temperature plates

52 and 56, work schematically shown in FIG. 3, a sintered mesh structure is attached to the inner side of the cavity, the upper layer and the lower layer are preferably 5-9 layers, the further layer is preferably 7 layers, the interlayer spacing is preferably 180-220 micrometers, the further layer spacing is preferably 200 micrometers, fluid adsorption is facilitated, and phase change heat exchange in the uniform temperature plates is realized. When the VC plate works, after the liquid medium at the bottom of the vacuum cavity absorbs the heat transferred to the fins from the water vapor at the bottom of the VC plate, the liquid medium is evaporated and diffused into the vacuum cavity, the heat is transferred to the condensation pipeline, and then the condensed liquid flows back through the sintering net which is attached to the inner wall of the VC plate and has capillary force. In principle, the VC plate is similar to a heat pipe, but different in conduction mode, the heat pipe is one-dimensional linear heat conduction, and the heat in the VC plate is conducted on a two-dimensional surface, so the efficiency is higher and the energy is more saved. The temperature equalizing plate is equivalent to a two-dimensional heat pipe, and the existence of the temperature equalizing plate can help heat to be quickly diffused in a plane range, so that the heat exchange efficiency is improved; the arrangement of the fin structure greatly increases the heat exchange area between the water vapor and the condenser, the heat exchange amount is increased, and the water yield is improved.

Preferably, the spoiler 552 is disposed in the middle of the cold water flow passage at the same distance from the partition cross plates at both sides. And have a plurality of welding points between the board of and both sides, through setting up a plurality of welding points, can increase the fixed connection between the board of both sides on the one hand, on the other hand can be used for further vortex, improves the heat transfer effect.

Preferably, a through hole is formed in the spoiler 552. The flow resistance brought by the spoiler 552 can be further reduced through the through holes, and meanwhile, more fluid can be guaranteed to flow through the inside of the spoiler 552, so that heat transfer is further enhanced.

In numerical simulation and experiments, the V-shaped included angle of the spoiler 552 cannot be too small, which can increase the flow resistance, and also cannot be too large, which can cause poor turbulence effect; the interval between the isolation diaphragm also can not be too big or too little, also can lead to flow resistance or vortex effect not good, and the clearance between spoiler 552 and the isolation diaphragm also can not be too little, too little can lead to flow resistance to increase, also can not be too big simultaneously, too greatly can lead to the vortex effect not good. Through a large amount of numerical simulation and experimental research, the optimal structural relation of the optimal heat exchange effect is found under the condition that the flow resistance is 50 KPa.

The spoiler is located two intermediate positions of keeping apart between the diaphragm, and the V font contained angle of spoiler 552 is A, and the height of spoiler is H, keeps apart the interval between the diaphragm and is S, then satisfies following requirement:

Sin(A)＝a*(S/H)-b*(S/H)²-c；

wherein a, b and c are parameters, 23.62< a <23.63,8.68< b <8.69,15.06< c < 15.08;

if calculated sin (a) >1, sin (a) ═ 1;

30°<a<150°，1.10<S/H<1.61；

further preferred, 60 ° < a <110 °, 1.2< S/H < 1.4;

more preferably, a is 23.627, b is 8.6875, and c is 15.07;

the spacing between the separating transverse plates is S, which is the distance between the opposite wall surfaces of the adjacent transverse plates.

The height of the spoiler is H, which is the distance between the wave peak and the wave trough of the flow surrounding plate.

Further preferably, a is gradually decreased and b and c are gradually increased with increasing S/H. Through so setting up, can make the relational expression of optimization further approach actual numerical simulation and experimental result, further improve the heat transfer effect.

Preferably, the S value range is 20< S <100mm, and the H value range is 18< H <90 mm;

preferably, the V-shaped included angle is a circular arc transition structure, as shown in fig. 3. Thereby further reducing drag.

When the arc transition structure is adopted, the V-shaped included angle is A, and is an included angle formed between extension lines of two straight lines forming the included angle.

Preferably, there are two cold water inlets 53 and two cold water outlets 54, respectively, so that two cold water flow passages are formed in parallel. Water enters the condenser from the two inlets respectively, so that the flow rate of cold water in the condenser is improved, and heat exchange is enhanced.

Preferably, the two cold water inlets 53 are located at the side portions of the plate type condensation member on both sides thereof, and the two cold water outlets 54 are located at the middle portion of the plate type condensation member. The spacing between the two cold water inlets 53 is greater than the spacing between the two cold water outlets 54 so that the cold water flows from the outside to the inside within the condenser and the flow area can cover the entire condenser.

Preferably, the plate-type condensation member 55 has a circular structure, and the design of the circular structure can improve the space utilization rate of the plate-type condensation member in the cylindrical tank body and increase the contact area between the steam and the condenser as much as possible. The condensing device consists of five layers of fins, temperature equalizing plates, cold water channels, temperature equalizing plates and fins from top to bottom, each layer plays the respective role in the condensing process, and the layered design is convenient to process.

Preferably, the plate-type condensation member is composed of an outer wall pipe, 5 partition horizontal plates and 6 spoilers, and the specific structure is as shown in fig. 4. 5 keep apart the parallel evenly distributed of diaphragm, 6 spoilers alternate between keeping apart the diaphragm to this reaches the purpose of streaming, realizes letting in the inside cold sea water of vortex pipeline and the abundant contact of upper and lower VC board, increase heat exchange efficiency.

Preferably, the lower wall surface of the upper temperature equalizing plate 52 and the upper wall surface of the lower temperature equalizing plate 56 are the upper and lower end caps of the plate-type condensation member 55, respectively.

The condenser 5 is inclined to the horizontal plane, preferably, the inclination angle is 14-16 degrees, and more preferably 15 degrees. When the inclination angle is too small, steam is easy to cover the upper surface of the condenser after being condensed on the upper surface of the condenser and does not flow down along with the inclination angle, so that the contact of the steam and the condenser is influenced, and the condensation efficiency is reduced; when the inclination is too big, its occupation space is great in the vertical direction, and projection area is less in the horizontal direction, is unfavorable for rather than contacting after the steam rises, reduces condensation efficiency.

The fin structure is designed, a plurality of strip plates with different lengths are perpendicularly connected with the circular bottom plate, the contact area of the condenser and water vapor is greatly increased on the side faces of the strip plates, the heat exchange speed is improved, and the condensed and liquefied water vapor is attached to the surface of the fin and then drips under the action of gravity.

Preferably, the fins 523 are the

fins

51 and 57.

Preferably, a through hole is formed in the spoiler 552. Through setting up the through-hole, can further alleviate the flow resistance, and guarantee that the fluid is intercommunication between the spoiler, avoid the local short circuit of spoiler.

Fresh water collecting system includes (outer) water collector 62 and lower (interior) water collector 61, it is located condenser 5 lower part to go up water collector 62, is located lower water collector 62 upper portion, goes up trompil 621 in the middle of the water collector 62, and lower water collector 61 is located the hole 621 lower part, and the fresh water clearing hole that can guarantee the condenser condensation through middle trompil gets into lower water collector 61. An upward vertical part 622 is arranged at the end part of the outermost end of the upper water collecting tray 62, a horizontal part 623 extending inwards is connected with the vertical part 622, and an upward inclined part 624 extending inwards along the horizontal part 623; the horizontal portion 623 is provided with a channel 625 for fresh water to flow into the lower water receiving tray or directly connect with a pipeline to deliver the fresh water to the fresh water collecting tank 13;

the lower water receiving tray 61 is located at the lower part of the upper water receiving tray opening 621, the lower water receiving tray 61 comprises an upright part 612 which is located at the end part of the lower water receiving tray 61 including the outermost end and is provided with an upward vertical part, an inclined part 613 which extends inwards and is inclined downwards and is connected with the upright part 622, and a channel 611 which is located at the central position, and the channel 611 is connected with a fresh water collecting tank.

According to the invention, by arranging the novel fresh water collecting system and arranging the inner and outer water receiving discs, the height of the outer disc is slightly higher than that of the inner disc, the fresh water collecting coverage area can reach the whole vacuum tank interface, and meanwhile, the gap between the inner disc and the outer disc can play a role in drainage. Through above-mentioned structure, realization fresh water that can be comprehensive collects, further improved the ability and the effect of sea water fresh water.

The fresh water collecting system consists of an inner ring water receiving tray, an outer ring water receiving tray, a fresh water collecting barrel and a fresh water pipeline, and fresh water flows into the fresh water collecting barrel under the action of gravity after being produced. The interior of the tank body is connected with the fresh water collecting barrel through a fresh water pipeline, so that the pressure intensity inside the tank body and the pressure intensity inside the fresh water collecting barrel are consistent, and the device works more stably. As shown in fig. 11, when the seawater desalination device works, the mist-like sprayed seawater absorbs heat and vaporizes when encountering the fin-type turbolator evaporator, the vapor rises and contacts with the integrated uniform-temperature plate fin condenser which continuously cools the seawater, the vapor liquefies when encountering cold and condenses into liquid drops, the liquid drops fall to the inner and outer annular water receiving trays under the action of gravity, and the liquid drops flow to the fresh water collecting barrel through the fresh water pipeline, so that the fresh water is collected.

Preferably, the seawater desalination system further comprises a vacuum system, the vacuum system comprises a vacuum tank 12, and the condenser 5, the upper water pan 62, the lower water pan 61 and the condensation end 8 of the loop heat pipe 2 are arranged in the vacuum system.

Note that the dimensions of the fresh water collection system shown in fig. 17 are merely the optimum dimensions.

Preferably, the vacuum system comprises a vacuum maintaining device, the device adopts a sealing structure to maintain the internal pressure of the device, and the internal pressure of the device is reduced by utilizing the Venturi principle to vacuumize, so that the boiling point of the seawater during evaporation is reduced. The venturi tube is placed at a seawater outlet, the seawater consumption is large, one part of the treated seawater enters the tank body for desalination, the other part of the treated seawater is directly discharged, the venturi tube is used for discharging, when cold water flows, the cross section of the venturi tube is suddenly reduced to increase the flow velocity, so that the pressure difference generated by the flow velocity is utilized to take away air in the tank, and the low-pressure state in the tank body is maintained, as shown in fig. 9. The port A is a liquid inlet, the port C is a liquid outlet, the sectional area of the position B is reduced, the flow speed of the position B is increased, the port D is communicated with the position B, and the pressure of the port D is reduced, so that air is discharged from the port D. The discharged seawater is connected with the port A, the port D is connected with the tank body, and the port C discharges water, so that the purpose of vacuumizing the vacuum tank is achieved. A mouth links to each other with condensation end waste water outlet, and D mouth links to each other with fresh water collection tank, and the waste water pipeline direct discharge that waste seawater behind the venturi is connected by C mouth. D is connected with a fresh water collecting tank which is communicated with the whole gas of the vacuum tank 12 to take out the air in the device and maintain the vacuum environment.

Preferably, the wastewater from the vacuum tank 12 after desalination of sea water is also discharged through the port a. Thereby further creating a vacuum.

Preferably, in order to utilize the heat of the evaporator absorbed in the non-evaporated seawater, a circulating spraying system is designed, and the non-evaporated seawater is sprayed for multiple times in a circulating manner to fully utilize the heat. As shown in fig. 10, the seawater desalination system further includes a seawater circulation spraying system, the seawater circulation spraying system is disposed in the vacuum system, the seawater circulation spraying system includes a circulation spraying pump, a spraying head 7 and a circulation pipeline, the spraying head 7 is disposed on the upper portion of the condensation end 8; the circulating spray pump pumps the seawater in the vacuum system into the spray header 7 and then sprays the seawater to the condensation end.

Preferably, the spray header 7 is connected with a return pipe. During operation, firstly, the seawater inlet and outlet valve is used for controlling spraying and water replenishing in the tank 12, when the height of seawater in the tank 12 reaches a certain height, the circulating spraying pump is started for circulating spraying, when the evaporated waste brine reaches a certain concentration, the circulating spraying pump stops working, the waste water outlet at the lower part of the tank body is opened, the strong brine is discharged through the waste water outlet, after the waste strong brine is drained out, the waste water outlet valve is closed, and water replenishing and circulating spraying are carried out again.

Through setting up the structure that sprays, can utilize not evaporating the evaporimeter heat that absorbs in the sea water, realize that the sea water turns into fresh water to the at utmost, realize the biggest utilization effect.

The spray head 7 is an atomizing spray head.

Preferably, a seawater concentration detection device is arranged in the tank body and used for detecting the concentration of seawater, and the controller automatically controls the seawater discharge according to the detected seawater concentration. If the measured seawater concentration exceeds a certain numerical value, the controller controls the circulating spray pump to stop working, the waste water outlet at the lower part of the tank body is opened, and the strong brine is discharged from the waste water outlet.

Preferably, a water level detection device is arranged in the tank body and used for detecting the water level height in the vacuum tank. When the water level is lower than certain data, the controller controls the circulating spray pump to stop working, and the valve of the water replenishing pipe is opened to replenish water. When the water level reaches a certain height, the water replenishing pipe valve is closed, and the circulating spraying pump starts to work.

Preferably, when the water level exceeds a certain value, for example, the water level is too high, for example, the water level approaches the height of the spray header, the circulation spray pump stops working, the waste water outlet at the lower part of the tank body is opened, and the seawater is discharged through the waste water outlet. When the water level reaches a certain height, the valve at the waste water outlet is closed, and the circulating spraying is performed again.

Preferably, the shower head 7 is an annular circular tube structure, and a plurality of shower heads are distributed on the circular tube.

Through the spraying structure and the arrangement thereof, intelligent operation can be realized, and the efficiency of seawater desalination is improved.

Preferably, as shown in fig. 6, the loop heat pipe is a plate CPL capillary pump, a transverse pipe falling-film evaporator (a structure shown in fig. 8) for evaporating seawater is preferably selected to serve as a condenser in the plate CPL capillary pump, a solar heat collection plate serves as an evaporator in the plate CPL capillary pump, the plate CPL capillary pump and the solar heat collection plate are connected by a capillary core pipeline, a liquid working medium absorbs heat in the plate CPL heat collection evaporator to evaporate, the liquid working medium is driven to flow by using capillary force, and no additional driving force is required to be provided for the liquid working medium outside; the liquid working medium flows in, absorbs heat, evaporates into steam, and the steam is discharged, thus the circulation is completed in a reciprocating way. .

Preferably, as shown in fig. 7, the evaporation end is a plate structure, and is composed of an upper cover plate with a vapor channel, a liquid return cavity base, a capillary core layer, a liquid header, a vapor header and the like. The upper cover plate is composed of a metal outer wall 211 and a steam channel 212, the liquid return cavity base is composed of a base outer wall 215 and a liquid channel 214, and the capillary layer 213 is positioned between the upper cover plate and the liquid return cavity base. The capillary core layer is arranged on the upper part of the liquid reflux cavity base and is tightly pressed by the upper cover plate, so that the liquid reflux channel is separated from the steam channel; the upper cover plate with the steam channel and the liquid return cavity are sealed by a tetrafluoro gasket 216 and a D05 sealant and are connected by bolts, so that the flat plate heat collection evaporator is detachable.

At least a portion of the liquid in the liquid channel enters the vapor channel through the capillary wick. When the heat-dissipating type steam-condensing heat-dissipating device works, the evaporator absorbs heat, liquid in the steam channel evaporates, liquid media in the liquid channel 214 also evaporates, evaporated gas is diffused to the steam channel 212 through fine holes in the capillary cores 213 and is gathered in the steam gathering box 217 and comes to the condensing end through an evaporation loop, the steam is dissipated and liquefied at the condensing end, and the liquefied media flow back to the inside of the liquid channel 214 through the capillary force of the capillary cores to complete a cycle and realize heat transfer. Compared with the traditional single-phase heat exchange, the double-phase heat exchange can improve the heat transfer efficiency and reduce the heat loss in the heat exchange process.

The solar heat collector comprises a solar heat collecting plate, and the upper surface of the evaporation end is attached to the lower surface of the solar heat collecting plate 1.

Preferably, the upper surface of the evaporation end is the solar heat collecting plate 1.

Preferably, the evaporation system is composed of a plate CPL capillary pump, a solar heat collecting plate, an electric heating plate and a fin type turbulent flow evaporator, and the specific structure is shown in FIG. 5.

Preferably, the solar heat collecting plate and the electric heating plate form a heat collecting system, the solar heat collecting plate and the electric heating plate are distributed on two sides of the plate type CPL capillary pump, the electric heating plate is arranged on the backlight side, the heat source mainly adopts solar heat collection, the electric heating plate provides electric auxiliary heating when necessary, and a heat conducting medium in the CPL capillary pump exchanges heat with phase to the heat dissipation plate type turbulence evaporator and is placed in the tank body to evaporate seawater.

Preferably, only solar collector panels or only electric heating panels are used. When only the electric heating plate is used, the electric heating plate is arranged at the upper part and/or the lower part of the evaporation end of the loop heat pipe.

Preferably, as shown in fig. 8, the condensation end 8 (i.e., a seawater evaporator) is of a tube-plate type heat exchange structure comprising an inlet header 82, an outlet header 86, an inlet heat exchange tube 83, an outlet heat exchange tube 85 and a plate group 84, the inlet header 82 is connected to the inlet heat exchange tube 83, the inlet heat exchange tube 83 is connected to the corresponding plate group 84, the plate group 84 is a heat exchange channel formed by combining two plates, the plate group 84 is connected to the outlet heat exchange tube 85, the outlet heat exchange tube 85 is connected to the outlet header 86, and steam from the evaporation end enters the inlet heat exchange tube 83 through the inlet header 82, then enters the plate group 84 through the inlet heat exchange tube 83, then enters the outlet heat exchange tube 85 after being subjected to heat exchange by the plate group 84, and then is. The inlet heat exchange tubes 83, outlet heat exchange tubes 85 and plate pack 84 are the primary components of heat exchange and preferably the inlet header 82 and outlet header 86 also participate in heat exchange. The condensation end 8 is soaked in seawater or the seawater is sprayed to the condensation end through a spraying device for heat exchange.

The invention provides a novel tube-plate type heat exchange structure, which can further reduce resistance, enlarge heat dissipation area and improve heat dissipation efficiency by combining tube plates. Especially, the heat exchanger with the function of seawater desalination spraying can improve the seawater desalination effect.

Preferably, the inlet heat exchange tubes 83 are multiple, and each inlet heat exchange tube 83 corresponds to one plate group 84. The plurality of plate groups are in a parallel spaced apart configuration. Preferably, the outlet heat exchange tubes 85 are plural, and each outlet heat exchange tube 85 corresponds to one plate group 84.

Preferably, the plate pack is vertically distributed. Thus, the spray water can fully exchange heat with the plate set.

Preferably, the inlet header 82 and the outlet header 86 are located on the same side of the plate package.

The inlet heat exchange tubes, the outlet heat exchange tubes and the plate pack are main components for heat exchange, and preferably, the inlet headers and the outlet headers also participate in heat exchange. The condensation end is soaked in seawater or the seawater is sprayed to the condensation end through a spraying device for heat exchange.

In numerical simulation and experiments, the distance between the plate groups cannot be too small, the flow resistance of spray water can be increased due to the too small distance, the spray water can not be well distributed on the whole heat exchange plate due to the too large distance, the heat exchange effect is not good, the spray water can not flow down without heat exchange due to the too large distance, the heat exchange short circuit is caused, the heat exchange effect is not good, and in the same way, the flow channel area of the heat exchange plate groups cannot be too large and cannot be too small, the heat exchange quantity is insufficient due to the too small distance, and the heat exchange quantity is too large due to the too large distance; the height of the heat exchange plate group can not be too large or too small, and the heat exchange effect is poor due to too large or too small height. The flow areas of the inlet heat exchange tubes and the outlet heat exchange tubes are also corresponding to the flow areas of the inside of the heat exchange plate group, and the flow areas cannot be too large or too small, so that the heat exchange effect is poor due to too large or too small flow areas. According to the invention, through a large amount of numerical simulation and experimental research, the optimal structural relationship of the optimal heat exchange effect is found, and the full utilization of heat is ensured.

The distance between adjacent plate groups is S1, the length of the plate groups is H1, the flow area of the plate groups is V1, the flow areas of the inlet heat exchange tubes and the outlet heat exchange tubes are the same, and the flow area of the inlet heat exchange tubes is V2, so that the following requirements are met:

(S1/H1) × 10 ═ a + b ═ LN (V2/V1 × 10); LN is a function of the logarithm of the number,

wherein a, b are parameters, 2.67< a < 2.68; 1.99< b < 2;

more preferably, a is 2.674, b is 1.996;

wherein 0.099< V2/V1< 0.13; 0.04< S1/H1< 0.05;

the spacing between adjacent plate groups is S1 the distance between the opposing walls of adjacent plate groups.

The length of the plate package H1 is the length parallel to the direction of fluid flow in the plate package, see fig. 8.

Further preferably, a is gradually increased and b is gradually increased with the increase of V2/V1. Through so setting up, can make the relational expression of optimization further approach actual numerical simulation and experimental result, further improve the heat transfer effect.

Preferably, in the evaporation system (i.e. the condensation end of the heat pipe), the evaporator 8 adopts 15 single radiating fins which are arranged in parallel at equal intervals, connected together in parallel by a header and finally fixed into a group by a radiating fin frame, and the structure is shown in fig. 8.

Preferably, a power device is arranged on a pipeline from the condensation end of the heat pipe to the evaporation end of the heat pipe (a solar thermal collector) and is used for driving the fluid subjected to heat exchange at the condensation end to be transmitted to the evaporation end for absorbing heat.

Further preferably, the power device is a drive pump.

The evaporator 8 is formed by laser welding and bulging technology, a fluid flow path in the evaporator is of a U-shaped structure, and small particles are distributed on the U-shaped path so as to achieve the purpose of turbulence, so that the inner wall of the evaporator is fully contacted with a fluid heat-conducting medium, and the heat transfer efficiency is improved.

The inlet header 82 and the outlet header 86 are connected to a steam inlet pipe 81 and a condensed water outlet pipe 87, respectively. Preferably, a flow stabilizer is provided in the inlet header vapor (fluid) inlet pipe 81, and the flow stabilizer 14 is configured as shown in FIGS. 12 and 13. The flow stabilizer 14 is a sheet structure provided on the cross section of the steam inlet pipe 81; the flow stabilizer 14 is formed by a square and regular octagonal structure, so that a square through hole 141 and a regular octagonal through hole 142 are formed. The side length of the square through-hole 141 is equal to the side length of the regular octagonal through-hole 142 as shown in fig. 1, the four sides 143 of the square through-hole are the sides 143 of four different regular octagonal through-holes, respectively, and the four mutually spaced sides 143 of the regular eight deformed through-hole are the sides 143 of four different square through-holes, respectively.

Two-phase flow and instability phenomena are widely present in heat exchange devices, such as loop heat pipes, because the presence of a vapor phase simultaneously entrains the flow of a liquid phase. The two-phase fluid entering the heat exchange equipment can generate a water hammer phenomenon caused by space expansion, and the heat exchange can be deteriorated due to the generation of a large amount. When the vapor and liquid phases of the two-phase working medium are not uniformly mixed and flow discontinuously, large-size liquid masses can occupy the vapor mass space at a high speed, so that the two-phase flow is unstable, equipment and a pipeline are severely impacted, strong shock and noise are generated, and the operation safety of the heat pipe equipment is seriously threatened.

The invention adopts a flow stabilizer with a novel structure, namely, the flow stabilizer in the loop heat pipe is subjected to field transfer and is applied to an inlet pipe at the evaporation end of the loop heat pipe. Since the steam inlet pipe 81 is connected to the inlet header 82, a water hammer phenomenon due to a space enlargement is generated when the steam-water mixture enters the inlet header 82. The invention adopts a new structure flow stabilizer, and has the following advantages:

1) the invention provides a novel flow stabilizer with a novel structure combining a square through hole and a regular octagonal through hole, wherein the included angles formed by the edges of the formed square hole and the regular octagonal hole are more than or equal to 90 degrees through the square and the regular octagon, so that fluid can fully flow through each position of each hole, and the short circuit of the fluid flow is avoided or reduced. The two-phase fluid is separated into the liquid phase and the gas phase by the flow stabilizer with the novel structure, the liquid phase is divided into small liquid masses, the gas phase is divided into small bubbles, the backflow of the liquid phase is inhibited, the gas phase is enabled to flow smoothly, the flow stabilizing effect is achieved, and the vibration and noise reduction effects are achieved. Compared with the current stabilizer in the prior art, the current stabilizer further improves the current stabilizing effect and is simple to manufacture.

2) According to the invention, through reasonable layout, the square and regular octagonal through holes are uniformly distributed, so that the fluid on the whole cross street is uniformly divided, and the problem of nonuniform division of the annular structure along the circumferential direction in the prior art is avoided.

3) According to the invention, the square holes and the regular octagonal through holes are uniformly distributed at intervals, so that the large holes and the small holes are uniformly distributed on the whole cross section, and the separation effect is better through the position change of the large holes and the small holes of the adjacent flow stabilizing devices.

4) According to the invention, the flow stabilizer is of a sheet structure, so that the flow stabilizer is simple in structure and low in cost.

The invention divides the gas phase and the liquid phase at all cross section positions of all heat exchange tubes, thereby realizing the contact area of the division of a gas-liquid interface and a gas phase boundary layer and a cooling wall surface on the whole heat exchange tube section and enhancing the disturbance, greatly reducing the noise and the vibration, and also leading the fluid entering the inlet header 82 to fully exchange heat with the seawater and strengthening the heat transfer.

Preferably, the flow stabilizers comprise two types, as shown in fig. 12 and 13, the first type is a square central flow stabilizer, and the square is positioned at the center of the steam inlet pipe or the condensation pipe, as shown in fig. 13. The second is a regular octagonal central flow stabilizer, which is located in the center of the steam inlet pipe or condenser pipe, as shown in fig. 12. Preferably, the two types of flow stabilizers are arranged adjacently, i.e. the adjacently arranged flow stabilizers are of different types. Namely, the regular octagonal central current stabilizer is adjacent to the square central current stabilizer, and the square central current stabilizer is adjacent to the regular octagonal central current stabilizer. According to the invention, the square holes and the regular octagon holes are uniformly distributed at intervals, so that the large holes and the small holes are uniformly distributed on the whole cross section, and through the position change of the large holes and the small holes of the adjacent flow stabilizing devices, the fluid passing through the large holes next passes through the small holes, and the fluid passing through the small holes next passes through the large holes to be further separated, so that the mixing of vapor and liquid is promoted, and the separation damping and noise reduction effects are better.

Preferably, the steam inlet pipe 81 is square in cross-section.

Preferably, the diameter of the steam inlet pipe 81 increases continuously along the direction of fluid flow. The main reasons are as follows: 1) by increasing the pipe diameter of the steam inlet pipe, the flowing resistance can be reduced, so that the steam evaporated in the steam inlet pipe continuously moves towards the direction of increasing the pipe diameter, and the circulating flow of the loop heat pipe is further promoted. 2) By increasing the pipe diameter of the steam inlet pipe, the impact phenomenon caused by the increase in the volume of the steam outlet can be reduced.

Preferably, the pipe diameter of the steam inlet pipe 81 is continuously increased more and more in the direction of the fluid flow. The amplitude change of the pipe diameter is a result obtained by a large number of experiments and numerical simulation by the applicant, and through the arrangement, the circulating flow of the loop heat pipe can be further promoted, the pressure is integrally uniform, and the impact phenomenon is reduced.

Preferably, a plurality of flow stabilizers are provided in the steam inlet pipe 81, with the closer to the inlet header 82, the smaller the spacing between the flow stabilizers. Let the distance from the inlet header 82 be H, and the spacing between adjacent flow stabilizers be S, S ═ F₁(H) I.e. S is a function of the height H as a variable, S' is the first derivative of S, satisfying the following requirements:

S’>0；

the primary reason is that vibration and its noise are increasing closer to the inlet header 82, and there is an increasing need to further mitigate vibration and noise. The distance between adjacent flow stabilizers needs to be set shorter and shorter.

The section from the outlet of the steam inlet pipe to the inlet header is suddenly enlarged, and the change of the space can cause the gas to rapidly flow out and gather upwards, so that the change of the space can cause the gathered vapor phase (vapor mass) to enter the condensation header from the position of the steam inlet pipe, the vapor mass moves upwards rapidly from the position of the connecting pipe due to the poor liquid density of the vapor (vapor), and the original space position of the vapor mass is pushed away from the liquid on the wall surface by the vapor mass and simultaneously rebounds rapidly and impacts the wall surface to form an impact phenomenon. The more discontinuous the gas (vapor) liquid phase, the larger the gas mass accumulation and the larger the water hammer energy. The impact phenomenon can cause larger noise vibration and mechanical impact, and damage to equipment. Therefore, in order to avoid the phenomenon, the distance between adjacent flow stabilizers is set to be shorter and shorter, so that the gas phase and the liquid phase are separated continuously in the fluid conveying process, and vibration and noise are reduced to the maximum extent.

Through the experiment discovery, through foretell setting, both can reduce vibrations and noise to the at utmost, can improve the heat transfer effect simultaneously.

It is further preferred that the distance between adjacent flow stabilizers be increasingly shorter the closer they are to the inlet header 82. I.e. S "is the second derivative of S, the following requirements are met:

S”<0；

experiments show that the vibration and noise can be further reduced by about 7%.

Preferably, a plurality of flow stabilizers are provided in the steam inlet pipe, the closer to the inlet header 82, the smaller the side length of the square. A distance H from the inlet header 82, a side length C of the square, and C ═ F₂(H) And C' is the first derivative of C, and meets the following requirements:

C’>0；

it is further preferred that the sides of the square increase in decreasing magnitude the closer they are to the inlet header 82. C' is the second derivative of C, and meets the following requirements:

C”<0。

see previous variations in the flow stabilizer spacing for specific reasons.

Preferably, the distance between adjacent flow stabilizers remains constant.

Preferably, the inner wall of the steam inlet pipe is provided with a gap, and the outer end of the flow stabilizer is arranged in the gap.

Preferably, the steam inlet pipe is formed by welding a multi-section structure, and a flow stabilizer is arranged at the joint of the multi-section structure.

Through analysis and experiments, the distance between the flow stabilizers cannot be too large, the vibration and noise reduction effect is poor if the distance is too large, meanwhile, the distance cannot be too small, the resistance is too large if the distance is too small, and similarly, the side length of a square cannot be too large or too small, and the vibration and noise reduction effect is poor or the resistance is too large, so that the vibration and noise reduction is optimized under the condition that the normal flow resistance (the total pressure bearing is less than 2.5Mpa or the on-way resistance of a single steam inlet pipe is less than or equal to 5Pa/M) is preferentially met through a large number of experiments, and the optimal relation of each parameter is arranged.

Preferably, the distance between adjacent flow stabilizers is S1, the side length of the square through hole is L1, the steam inlet pipe is of a square cross section, and the side length of the square cross section of the steam inlet pipe is L2, so that the following requirements are met:

S1/L2＝a*(L1/L2)²+b*(L1/L2)-c

wherein a, b, c are parameters, wherein 39.8< a <40.1,9.19< b <9.21, 0.43< c < 0.44;

9<L2<58mm；

1.9<L1<3.4mm；

15<S1<31mm。

more preferably, a is 39.87, b is 9.20, c is 0.432

Further preferably, a, b are larger and c is smaller as L1/L2 is increased.

Preferably, the side length L1 of the square through hole is the average of the inner and outer side lengths of the square through hole, and the side length L2 of the square cross-section of the steam inlet pipe is the average of the inner and outer side lengths of the steam inlet pipe.

Preferably, the outer length of the square through hole is equal to the inner length of the square cross-section of the steam inlet pipe.

Preferably, as L2 increases, L1 also increases. However, as L2 increases, the magnitude of the increase in L1 decreases. The change of the law is obtained through a large amount of numerical simulation and experiments, and the heat exchange effect and the noise are further improved through the change of the law.

Preferably, S1 decreases as L2 increases. However, as L2 increases, the magnitude of the decrease in S1 decreases. The change of the rule is obtained through a large amount of numerical simulation and experiments, and the heat exchange effect and the noise are further improved and reduced through the change of the rule.

For other parameters, such as the wall thickness of the pipe and the wall thickness of the shell, the parameters are set according to normal standards.

Preferably, the fluid within the heat pipe is water.

Preferably, the pipe diameter of the steam inlet pipe is larger than that of the return pipe. The resistance of the return pipe is mainly increased, and the resistance of the steam inlet pipe is reduced, so that steam flows from the evaporation part more easily, and the loop heat pipe forms circulation better.

Although the present invention has been described with reference to the preferred embodiments, it is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An evaporator inlet pipe design method comprises an inlet header, an outlet header and a heat exchange component connected between the headers, wherein the inlet header and the outlet header are respectively connected with a steam inlet pipe and a condensate outlet pipe; the flow stabilizer is composed of a square structure and a regular octagonal structure, so that a square through hole and a regular octagonal through hole are formed, the side length of the square through hole is equal to that of the regular octagonal through hole, four sides of the square through hole are respectively sides of four different regular octagonal through holes, and four mutually spaced sides of the regular octagonal deformed through hole are respectively sides of four different square through holes; the inlet pipe is designed in the following way: the diameter of the steam inlet pipe increases continuously along the direction of fluid flow.

2. The design method as claimed in claim 1, wherein the pipe diameter of the steam inlet pipe is increased more and more along the direction of fluid flow.

3. A seawater desalination system comprising an evaporation system, a condensation system and a fresh water collection system, wherein seawater is evaporated in the evaporation system to generate steam, the steam is then condensed in the condensation system to become fresh water, and the fresh water is then collected by the fresh water collection system, and the evaporation system comprises a steady flow evaporator designed according to the method of claims 1-2.