CN110285607B - Horizontal impact falling-film evaporator and method - Google Patents
Horizontal impact falling-film evaporator and method Download PDFInfo
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- CN110285607B CN110285607B CN201910433496.4A CN201910433496A CN110285607B CN 110285607 B CN110285607 B CN 110285607B CN 201910433496 A CN201910433496 A CN 201910433496A CN 110285607 B CN110285607 B CN 110285607B
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- shell
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- liquid distributor
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- 239000011552 falling film Substances 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 11
- 238000001704 evaporation Methods 0.000 claims abstract description 49
- 230000008020 evaporation Effects 0.000 claims abstract description 41
- 239000007788 liquid Substances 0.000 claims abstract description 39
- 239000003507 refrigerant Substances 0.000 claims abstract description 35
- 239000002826 coolant Substances 0.000 claims abstract description 6
- 230000000694 effects Effects 0.000 claims description 5
- 239000010408 film Substances 0.000 claims description 5
- 230000008569 process Effects 0.000 claims description 4
- 239000011148 porous material Substances 0.000 claims description 2
- 238000001816 cooling Methods 0.000 abstract description 4
- 230000009471 action Effects 0.000 abstract description 2
- 238000009825 accumulation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000003116 impacting effect Effects 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000005057 refrigeration Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B39/00—Evaporators; Condensers
- F25B39/04—Condensers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2339/00—Details of evaporators; Details of condensers
- F25B2339/02—Details of evaporators
- F25B2339/021—Evaporators in which refrigerant is sprayed on a surface to be cooled
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
The invention discloses a horizontal impact type falling-film evaporator and a method, belonging to the technical field of evaporation. This evaporimeter mainly includes exhaust passage, evaporating pipe, casing and liquid distributor, its characterized in that: the top of the shell is provided with a steam outlet and a coolant inlet, and the bottom of the shell is provided with a refrigerant outlet; the bottom of the liquid distributor is provided with a nozzle; fins are arranged on the outer wall of the first row of evaporation tubes; the rib is provided with a liquid hole; according to the horizontal impact falling-film evaporator provided by the invention, the jet speed is increased by installing the nozzle at the bottom of the liquid distributor, so that the heat exchange rate is increased, and the fins are arranged on the outer wall of the first row of evaporation tubes to slow down impact jet, so that the refrigerant can fully exchange heat among the evaporation tubes, and the heat exchange quantity is increased. Under the action of impingement cooling, the heat exchange efficiency of the integral falling film evaporator is improved. The device has novel structure and high heat exchange rate.
Description
Technical Field
The invention relates to a horizontal impact type falling-film evaporator and a method, belonging to the technical field of evaporation.
Background
The falling film evaporator is a new type evaporator, which has the advantages of small refrigerant filling amount, small equipment volume, good oil return performance and the like, and is widely applied to systems such as refrigeration air conditioners, compressor units and the like. The heat transfer mechanism of the falling film evaporator is very complex, and the heat transfer coefficient of the falling film evaporator is influenced by various factors such as refrigerant types, operation conditions, evaporation tube parameters, surface flow forms and the like. The limiting factors of the operation condition are more, and the required flow rate of the refrigerant can not be too large when the refrigerant exchanges heat with the substances in the evaporation tube, so that the contact time of cold and hot fluids is prolonged, and the heat exchange quantity is increased. However, the heat transfer rate is slow due to the slow flow rate, so that the heat exchange efficiency of the refrigerant flowing between the evaporation tubes is limited, and the overall heat exchange efficiency of the falling film evaporator is low.
Disclosure of Invention
The invention provides a horizontal impact type falling-film evaporator and a method thereof, aiming at the problems of low heat exchange efficiency and the like of the existing falling-film evaporator.
The utility model provides a horizontal impact falling film evaporator, includes exhaust passage, evaporating pipe, casing and liquid distributor, its characterized in that: the shell is in a cylindrical shape which is horizontally arranged; a liquid distributor is horizontally arranged at the middle upper part in the shell, nozzles are uniformly arranged at the bottom of the liquid distributor, and an exhaust channel is reserved between two ends of the liquid distributor and the inner wall of the shell; horizontally arranging an evaporation tube array in the middle and the lower part of the interior of the shell, wherein the arrangement mode of evaporation tubes in the evaporation tube array is a fork-row or sequential-row mode; a steam outlet is formed in the center line of the top of the shell, a refrigerant inlet communicated with the middle of the liquid distributor is also formed in the middle of the steam outlet, and a refrigerant outlet is formed in the center line of the bottom of the shell; the row of evaporation tubes closest to the liquid distributor in the evaporation tube array is called as a first row of evaporation tubes; each evaporating pipe of the first row of evaporating pipes corresponds to the corresponding nozzle and is just positioned right below the corresponding nozzle; the outer wall of the first row of evaporation tubes is provided with fins which are symmetrically arranged by taking the corresponding nozzle as the center; and liquid holes are arranged on the fins from the side contacted with the evaporating pipe.
The working method of the horizontal impact falling-film evaporator is characterized by comprising the following working processes: the refrigerant firstly enters a liquid distributor through a refrigerant inlet, then impacts the outer wall of a first row of evaporation tubes through a nozzle, the impacted jet flows to fins, the jet flows out of a liquid hole after the jet is decelerated through the fins, and then flows to the next row of evaporation tubes along the fins and the outer wall of the evaporation tubes in a liquid film shape; to improve the stability of the evaporator operation, the shell should be filled with refrigerant in the region of the shell bottom 1/3; the refrigerant evaporated in the impact falling film heat exchange process is discharged out of the evaporator from the steam outlet at the top of the shell through the exhaust channel, and the refrigerant which is not evaporated is discharged out of the evaporator from the refrigerant outlet at the bottom of the shell.
The invention has the beneficial effects that: the horizontal impact falling-film evaporator provided by the invention has the advantages of novel structure and high heat exchange rate. The jet flow speed is improved by installing the nozzle at the bottom of the liquid distributor, so that the heat exchange rate and efficiency of the first row of evaporation tubes are improved, fins are arranged on the outer wall of the first row of evaporation tubes to slow down impact jet flow, so that the refrigerant can fully exchange heat between the evaporation tubes, and the heat exchange efficiency of the rear row of evaporation tubes is improved. Under the action of impingement cooling, the heat exchange efficiency of the integral falling film evaporator is improved.
The horizontal impact falling-film evaporator is characterized in that: the arrangement mode of the liquid holes arranged on the fins is a fork arrangement mode, so that the impact jet flow is favorably slowed down, and a better liquid film is smoothly formed on the tube wall.
The horizontal impact falling-film evaporator is characterized in that: in order to make the jet flow impacting on the first row of evaporation tubes reduce speed and further form a better liquid film on the lower end of the tube wall, the fins are provided with anglesa45-70 degrees; if the opening angle is too small, the flow rate of the coolant flowing to the next row of evaporation tubes through the liquid holes is too large, and the heat exchange is insufficient; if the opening angle is too large, the retention time of the coolant on the fins is too long, and the accumulation phenomenon is formed, so that the further heat exchange performance of the coolant and the lower row of evaporation tubes is influenced.
The horizontal impact falling-film evaporator is characterized in that: according to different nozzles, jet flow distances and refrigerants, in order to achieve the effect of impingement cooling, the jet flow Reynolds number of the nozzle is controlled to be 2.1 multiplied by 105-2.1×106(ii) a The Reynolds number is too small to achieve the effect required by impingement cooling; the overlarge Reynolds number not only increases difficulty in the arrangement of the fins, but also sharply increases impact force on the first row of evaporation tubes, thereby seriously affecting heat exchange performance.
The horizontal impact falling-film evaporator is characterized in that: the falling film evaporator adopts the liquid distributor with a 5-layer pore plate structure, so that not only can gas-liquid separation equipment be saved, but also better liquid distribution performance can be achieved.
Drawings
FIG. 1 is a schematic view of the overall structure of the present invention;
FIG. 2 is a schematic cross-sectional view of a fin;
FIG. 3 is a schematic view of the impact effect of the nozzle and the fins
Number designation in the figures: 1. the refrigerant evaporator comprises a steam outlet, 2 refrigerant inlets, 3 exhaust channels, 4 evaporation tubes, 5 refrigerant outlets, 6 shells, 7 fins, 8 nozzles, 9 liquid distributors and 10 liquid holes.
Detailed description of the invention
In order to make those skilled in the art better understand the technical solution of the present invention, the present invention is further described in detail below with reference to fig. 1, fig. 2 and fig. 3.
The refrigerant firstly enters a liquid distributor 9 through a refrigerant inlet 2, then impacts the outer wall of a first row of evaporation tubes 4 through a nozzle 8, the impacted jet flows to a fin 7, the jet flows out of a liquid hole 10 after the jet is decelerated through the fin 7, and then flows to a lower row of evaporation tubes 4 along the fin 7 and the outer wall of the evaporation tubes 4 in a liquid film shape; to improve the stability of the evaporator operation, the shell 6 should be filled with refrigerant in the region of the bottom 1/3 to reduce the effect of the bottom coolant temperature dip on the instability of the evaporative heat transfer; the refrigerant evaporated during the falling film impingement heat exchange exits the evaporator through the exhaust channel 3 from the vapor outlet 1 at the top of the shell 6 and the unevaporated refrigerant exits the evaporator through the refrigerant outlet 5 at the bottom of the shell 6.
The invention can realize geometric scaling of the nozzle and the fins according to different refrigerant requirements. The above description is only an exemplary embodiment of the present invention, and it should be noted that, for those skilled in the art, modifications and variations can be made without departing from the technical principle of the present invention and still fall within the protective scope of the present invention.
Claims (4)
1. The utility model provides a horizontal impact falling film evaporator, includes exhaust passage (3), evaporating pipe (4), casing (6) and liquid distributor (9), its characterized in that:
the shell (6) is in a cylindrical shape which is horizontally arranged;
a liquid distributor (9) is horizontally arranged at the middle upper part in the shell (6), nozzles (8) are uniformly arranged at the bottom of the liquid distributor (9), and an exhaust channel (3) is reserved between two ends of the liquid distributor (9) and the inner wall of the shell (6);
an evaporation tube array is horizontally arranged at the middle part and the lower part of the interior of the shell (6), wherein the arrangement mode of the evaporation tubes (4) in the evaporation tube array is a fork-type or sequential arrangement mode;
a steam outlet (1) is formed in the middle line of the top of the shell (6), a refrigerant inlet (2) communicated with the middle of the liquid distributor (9) is further formed in the middle of the steam outlet (1), and a refrigerant outlet (5) is formed in the middle line of the bottom of the shell (6);
one row of evaporation tubes in the evaporation tube array, which is closest to the liquid distributor (9), is called as a first row of evaporation tubes (4); each evaporating pipe of the first row of evaporating pipes (4) corresponds to a corresponding nozzle and is just positioned right below the corresponding nozzle;
fins (7) are arranged on the outer wall of the first row of evaporation tubes (4), and the fins (7) are symmetrically arranged by taking the corresponding nozzle (8) as the center; liquid holes (10) are formed on the fins (7) from the side in contact with the evaporation tube (4);
the arrangement mode of the liquid holes (10) is a fork arrangement mode;
the angle of the fins (7)aIs 45-70 degrees.
2. The horizontal impingement falling film evaporator of claim 1 wherein: the Reynolds number of the jet of the nozzle (8) is 2.1X 105-2.1×106。
3. The horizontal impingement falling film evaporator of claim 1 wherein: the liquid distributor (9) is of a 5-layer pore plate structure.
4. The working method of the horizontal impact falling-film evaporator according to claim 1, characterized by comprising the following working processes:
the refrigerant firstly enters a liquid distributor (9) through a refrigerant inlet (2), then impacts the outer wall of a first row of evaporation tubes (4) through a nozzle (8), the impacted jet flows to fins (7), the jet flows out of a liquid hole (10) after the speed of the jet is reduced through the fins (7), and then the jet flows to a lower row of evaporation tubes (4) along the fins (7) and the outer wall of the evaporation tubes (4) in a liquid film shape; to improve the stability of the evaporator operation, the shell (6) should be filled with refrigerant in the region of the bottom 1/3 to reduce the effect of instability on the evaporative heat transfer due to a sudden drop in the bottom coolant temperature; the refrigerant evaporated in the impact falling film heat exchange process is discharged out of the evaporator from the steam outlet (1) at the top of the shell (6) through the exhaust channel (3), and the non-evaporated refrigerant is discharged out of the evaporator from the refrigerant outlet (5) at the bottom of the shell (6).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910433496.4A CN110285607B (en) | 2019-05-23 | 2019-05-23 | Horizontal impact falling-film evaporator and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910433496.4A CN110285607B (en) | 2019-05-23 | 2019-05-23 | Horizontal impact falling-film evaporator and method |
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| Publication Number | Publication Date |
|---|---|
| CN110285607A CN110285607A (en) | 2019-09-27 |
| CN110285607B true CN110285607B (en) | 2021-06-22 |
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| CN201910433496.4A Active CN110285607B (en) | 2019-05-23 | 2019-05-23 | Horizontal impact falling-film evaporator and method |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000304377A (en) * | 1999-04-23 | 2000-11-02 | Daikin Ind Ltd | Absorber for water-cooled absorption refrigerating device |
| CN104457040A (en) * | 2014-11-13 | 2015-03-25 | 广东申菱空调设备有限公司 | Spray-type falling film evaporator and liquid level control method thereof |
| CN205425941U (en) * | 2016-04-01 | 2016-08-03 | 山东绿特空调系统有限公司 | Liquid distributor of horizontal falling film evaporation ware |
| CN106123400A (en) * | 2016-07-06 | 2016-11-16 | 杭州赛富特设备有限公司 | A kind of falling film type evaporation device of band gravity separatory |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10220914A (en) * | 1997-02-07 | 1998-08-21 | Osaka Gas Co Ltd | Plate type evaporator and absorbing device of absorbing type freezer |
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2019
- 2019-05-23 CN CN201910433496.4A patent/CN110285607B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000304377A (en) * | 1999-04-23 | 2000-11-02 | Daikin Ind Ltd | Absorber for water-cooled absorption refrigerating device |
| CN104457040A (en) * | 2014-11-13 | 2015-03-25 | 广东申菱空调设备有限公司 | Spray-type falling film evaporator and liquid level control method thereof |
| CN205425941U (en) * | 2016-04-01 | 2016-08-03 | 山东绿特空调系统有限公司 | Liquid distributor of horizontal falling film evaporation ware |
| CN106123400A (en) * | 2016-07-06 | 2016-11-16 | 杭州赛富特设备有限公司 | A kind of falling film type evaporation device of band gravity separatory |
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| Publication number | Publication date |
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| CN110285607A (en) | 2019-09-27 |
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