CN102060345A - Novel and efficient seawater desalination evaporator - Google Patents

Abstract

The invention discloses a novel high-efficiency seawater desalination evaporator, which is mainly composed of a vertical airtight container, a water vapor chamber, an upper flue gas chamber, a water inlet chamber, a heat exchange chamber, a lower flue gas chamber, a sewage discharge chamber and the like. In the present invention, the flue gas passes through the tapering nozzle of the annular channel to release heat on the outer wall of the heat transfer tube, which not only makes the maximum use of the flue gas heat, but also achieves a good effect of convective heat exchange between the two; The technology of using high-pressure seawater to form a high-speed rotating water film to absorb heat from the heat transfer tube not only achieves a good effect of convective heat transfer between the two, but also creates good conditions for the low-temperature evaporation of seawater, and makes the generated water Steam can be vented automatically. Therefore, the present invention has the characteristics of high heat source energy utilization rate, good heat transfer effect, good seawater evaporation effect, and automatic discharge of water vapor, so it can meet the needs of modern large-scale seawater desalination system engineering.

Description

New high-efficiency seawater desalination evaporator

technical field

The invention relates to the technical field of seawater desalination, in particular to a novel high-efficiency seawater desalination evaporator.

Background technique

There are more than 20 existing seawater desalination technologies. Reverse osmosis, low-temperature multi-effect distillation, multi-stage flash evaporation, freezing and electrodialysis are the most commonly used seawater desalination technologies. It is one of the earlier and more mature methods applied in technology. The maximum evaporation temperature of seawater in this desalination technology is lower than 70°C. It is characterized in that a series of horizontal tube spray falling film evaporators are connected in series, with a certain amount of steam input, through multiple evaporation and condensation, and the subsequent one-effect The evaporation temperature is lower than that of the previous effect, so that the desalination process of distilled water that is many times the amount of steam is obtained. Due to the energy saving of this technology, it has developed rapidly in recent years, and the scale of the device has been increasing day by day, and the cost has been reduced day by day. However, the main equipment in this technology, the horizontal tube spray falling film evaporator, has the disadvantages of low energy utilization rate and low heat transfer efficiency. , which directly causes the problem that the single-machine water production capacity of the device is not high, so it is of great significance to develop a new type of seawater desalination evaporator with higher energy utilization rate and higher heat transfer efficiency to replace the horizontal tube spray falling film evaporator .

Contents of the invention

The purpose of the present invention is to provide a new high-efficiency seawater desalination evaporator, which has the characteristics of high energy utilization rate, good heat transfer effect and large desalinated water output, and can meet the needs of modern large-scale seawater desalination system engineering.

For realizing the above object, technical solution of the present invention is:

The invention is a new high-efficiency seawater desalination evaporator, which is mainly composed of a vertical airtight container, a water vapor chamber, an upper flue gas chamber, a water inlet chamber, a heat exchange chamber, a lower flue gas chamber, a blowdown chamber and multiple vertical transmission pipes. The heat pipe is composed of; the water vapor chamber, the upper flue gas chamber, the water inlet chamber, the heat exchange chamber, the lower flue gas chamber, and the blowdown chamber are arranged in a vertical airtight container from top to bottom; the top of the water vapor chamber There is a water vapor outlet, a flue gas outlet on the wall of the upper flue gas chamber, a water inlet on the wall of the water inlet chamber, a flue gas inlet on the wall of the lower flue gas chamber, and a sewage outlet at the bottom of the sewage discharge chamber; Vertical heat transfer tubes are longitudinally arranged in a vertical airtight container, and each heat transfer tube runs through the space where the upper flue gas chamber, water inlet chamber, heat exchange chamber and lower flue gas chamber are located. It is connected to the end edge of the hole on the bottom surface of the water vapor chamber and the edge of the hole on the top surface of the sewage chamber, so that the hollow inner cavity of the heat transfer tube passes through the water vapor chamber and the sewage chamber; each heat transfer tube is covered with a heat-insulating concentric reducer Each different-diameter tube runs through the space where the water inlet chamber and the heat exchange chamber are located. Make the annular channel between the heat transfer tube and the different diameter tube pass through the upper flue gas chamber and the lower flue gas chamber; between the different diameter pipe section in the water inlet space and the heat transfer tube, arrange multiple rows of nozzles symmetrically along the circumference, and the nozzles pass through The space of the water inlet chamber is tangent to the inner cavity of the heat transfer tube, and the outlet of the nozzle is tangent to the inner wall of the heat transfer tube.

The different-diameter pipe section in the water inlet space is a round pipe with a slightly larger radius than the heat transfer pipe, and the different-diameter pipe section in the heat exchange chamber space is a tapered pipe with a radius that gradually decreases from bottom to top.

After adopting the above scheme, the flue gas with a certain pressure flows into the lower flue gas chamber from the flue gas inlet, and then the flue gas flows from the lower flue gas chamber into the tapering nozzle with an annular channel and automatically accelerates, and the flue gas at the top of the heat exchange chamber The gas velocity reaches the maximum, and maintains a nearly constant flow rate, flows through the water inlet chamber to the upper flue gas chamber, and is discharged from the flue gas outlet. When the thin layer of flue gas surrounding the heat transfer tube scours the outer wall of the heat transfer tube to release heat, the convective heat transfer area corresponding to the unit volume of flue gas is large, and the increase of the flue gas velocity increases the convective heat transfer coefficient, so the device Not only the energy utilization rate of the flue gas is high, but also the heat transfer effect of the flue gas to the heat transfer tube is very good. The high-pressure seawater boosted by the feed pump flows into the water inlet chamber from the water inlet, and then the seawater is sprayed from the circumferentially symmetrical nozzles to the inner wall of the heat transfer tube at high speed along the tangential direction. Under the action of centrifugal force, the sea water forms a circle along the inner wall of the heat transfer tube. A thin rotating film of water flows down to the blowdown chamber and out through the blowdown outlet. When the rotating water film scours the inner wall of the heat transfer tube to absorb heat, compared with the downward flow of ordinary falling film, the seawater not only flows faster and easily forms turbulent flow to enhance heat transfer, but also the movement distance of seawater in the heat transfer tube becomes longer, so the unit mass The convective heat transfer area corresponding to seawater becomes larger, and the convective heat transfer coefficient becomes larger, so the heat transfer effect of the heat transfer tube to seawater is very good. At the same time, due to the centrifugal force and entrainment force of the rotating water film, a certain degree of vacuum can be generated in the inner cavity of the heat transfer tube, and seawater can be evaporated at low temperature. good results. Due to the centrifugal force of the rotating water film, the water vapor generated by the evaporation of seawater will be quickly discharged from the inner cavity of the heat transfer tube, rise to the water vapor chamber, and be automatically discharged from the water vapor outlet.

To sum up, in the present invention, the technology that the flue gas passes through the annular channel (converging nozzle) with tapered cross-section to release heat from the heat transfer tube not only maximizes the utilization of the heat of the flue gas, but also makes the gap between the two The convective heat exchange achieves very good results; the technology of seawater absorbing heat from the heat transfer tube through the rotating water film not only makes the convective heat exchange between the two achieve a good effect, but also creates a good environment for the low-temperature evaporation of seawater. Conditions, and make the generated water vapor can be discharged automatically. Therefore, the present invention has the characteristics of high heat source energy utilization rate, good heat transfer effect, good seawater evaporation effect, and automatic discharge of water vapor, so it can meet the needs of modern large-scale seawater desalination system engineering.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a sectional front view of the present invention;

Fig. 2 is a sectional view along line A-A of Fig. 1;

Fig. 3 is a sectional view along line B-B of Fig. 1;

Fig. 4 is a working principle diagram of the present invention.

Detailed ways

As shown in Figure 1, the present invention is a new high-efficiency seawater desalination evaporator, which mainly consists of a vertical airtight container 10, a water vapor chamber 1, an upper flue gas chamber 2, a water inlet chamber 3, a heat exchange chamber 4, a lower smoke chamber The air chamber 5, the blowdown chamber 6, a plurality of vertical heat transfer pipes 7 and a plurality of different diameter pipes 8 are composed.

The water vapor chamber 1 , upper flue gas chamber 2 , water inlet chamber 3 , heat exchange chamber 4 , lower flue gas chamber 5 , and blowdown chamber 6 are arranged in a vertical airtight container 10 from top to bottom.

The top of the water vapor chamber 1 is provided with a water vapor outlet 11, the wall of the upper smoke chamber 2 is provided with a smoke outlet 21, the wall of the water inlet chamber 3 is provided with a water inlet 31, and the wall of the lower smoke chamber 5 is provided with a smoke inlet 51. The bottom of the sewage chamber 6 is provided with a sewage outlet 61.

A plurality of vertical heat transfer tubes 7 are regularly arranged inside the vertical airtight container 10, and each heat transfer tube runs through the space where the upper flue gas chamber 2, the water inlet chamber 3, the heat exchange chamber 4, and the lower flue gas chamber 5 are located. , the two ends of each heat transfer tube 7 are respectively connected to the opening edge 12 on the bottom surface of the steam chamber 1 and the opening edge 62 on the top surface of the sewage chamber, and the hollow cavity 71 of the heat transfer pipe 7 runs through the water vapor chamber 1 and the sewage chamber 6. Each heat transfer tube 7 is covered with an insulated concentric reducer 8, and each reducer 8 runs through the space where the water inlet chamber 3 and the heat exchange chamber 4 are located, and the reducer 8 in the space of the water inlet chamber 3 The tube section is a round tube 82 with a slightly larger radius than the heat transfer tube 7, and the tube section of the reducer tube 8 in the space of the heat exchange chamber 4 is a reducer tube 83 whose radius gradually decreases from bottom to top. An annular channel 81 is formed between the heat transfer tubes 7, at the upper end of the annular channel 81 is an annular outlet 84 with a smaller diameter (as shown in Figure 2), and at the lower end of the annular channel is an annular inlet 85 with a larger diameter ( As shown in Figure 3). The two ends of each different-diameter tube 8 are respectively connected to the opening edge 22 on the bottom surface of the upper flue gas chamber 2 and the opening edge 52 on the top surface of the lower flue gas chamber 5, so that the ring shape between the heat transfer tube 7 and the different-diameter tube 8 The channel 81 runs through the upper flue gas chamber 2 and the lower flue gas chamber 5 . Between the pipe section of the reducing pipe 8 in the water inlet space and the heat transfer pipe 7, multiple rows of nozzles 9 are arranged symmetrically along the circumference. The number of rows of nozzles 9 is selected according to the pressure of the inlet water. When the inlet water pressure is high , only one row of nozzles 9 can be arranged. The nozzle 9 penetrates the space of the water inlet chamber 3 and the inner cavity 71 of the heat transfer tube 7 , and the outlet of the nozzle 9 (shown in FIG. 2 ) is tangent to the inner wall of the heat transfer tube 7 .

Working principle of the present invention:

As shown in Figure 4, flue gas with a certain pressure flows into the lower flue gas chamber 5 from the flue gas inlet 51, and then the flue gas flows from the lower flue gas chamber 5 into the converging nozzle with the annular passage 81 and automatically accelerates, in the water inlet chamber 3 The flue gas velocity at the bottom surface 32 reaches the maximum, and maintains a nearly constant flow rate, flows through the water inlet chamber to the upper flue gas chamber 2, and is discharged from the flue gas outlet 21. When the thin layer of flue gas surrounding the heat transfer tube scours the outer wall 72 of the heat transfer tube 7, a strong convective heat exchange takes place between the flue gas and the outer wall 72 of the heat transfer tube 7, and the heat transfer tube 7 absorbs most of the heat from the flue gas. The high-pressure seawater boosted by the feedwater pump flows into the water inlet chamber 3 from the water inlet 31, and then the seawater is sprayed from the circumferentially symmetrical nozzle 9 to the inner wall 73 of the heat transfer tube 7 at a high speed in the tangential direction. A very thin high-speed rotating water film is formed on the inner wall 73 of the heat transfer pipe 7 to flow downward until the blowdown chamber 6 and flow out from the blowdown port 61 . When the high-speed rotating water film scours the inner wall 73 of the heat transfer tube 7, a strong convective heat exchange takes place between the rotating water film and the inner wall of the heat transfer tube 7, and the rotating water film absorbs most of the heat from the heat transfer tube 7. Due to the centrifugal force and entrainment force of the rotating water film, the inner cavity 71 of the heat transfer tube 7 generates a certain degree of low vacuum, and the seawater can be evaporated at a low temperature. good results. The water vapor produced by the evaporation of seawater will be expelled out of the inner cavity 71 of the heat transfer tube 7 due to the centrifugal force of the rotating water film, rise to the water vapor chamber 1, and be automatically discharged from the water vapor outlet 11.

The above is only a preferred embodiment of the present invention, and the arrangement of the inlet and outlet pipelines of each chamber can be various, so the scope of the present invention can not be limited with this, that is, the equivalents made according to the patent scope of the present invention and the contents of the description Changes and modifications should still fall within the scope covered by the patent of the present invention.

Claims (2)

1. new and effective seawater desalination evaporators is characterized in that: it mainly by vertical enclosed container, water steam chamber, go up smoke chamber, intake chamber, Heat Room, smoke chamber, blowdown chamber and the vertical heat-transfer pipe of Duo Gen are formed down; Described water steam chamber, last smoke chamber, intake chamber, Heat Room, following smoke chamber, blowdown chamber are arranged in the vertical enclosed container from top to bottom; Described water steam chamber top is provided with steam outlet, and last smoke chamber wall is provided with exhanst gas outlet, and the intake chamber wall is provided with water-in, and following smoke chamber wall is provided with gas approach, and bottom, blowdown chamber is provided with sewage draining exit; Described many vertical heat-transfer pipes longitudinally are arranged in the vertical enclosed container, every heat-transfer pipe all runs through smoke chamber, intake chamber, Heat Room and following space, smoke chamber place, every heat-transfer pipe two ends are connected to water steam chamber bottom surface perforate ora terminalis and blowdown chamber end face perforate ora terminalis, make the hollow cavity of heat-transfer pipe connect water steam chamber and blowdown chamber; Every heat-transfer pipe outside all is with one and thoroughly does away with hot concentric reducer, every taper(ed)pipe all runs through intake chamber, space, Heat Room place, every taper(ed)pipe two ends are connected to smoke chamber bottom surface perforate ora terminalis and following smoke chamber end face perforate ora terminalis, make that the circular channel between heat-transfer pipe and the taper(ed)pipe connects upward smoke chamber and following smoke chamber; Be between intake chamber spatial reducing pipeline section and the heat-transfer pipe and arrange that along the symmetric multiple row nozzle of circumference, nozzle connects intake chamber space and heat-transfer pipe inner chamber, and jet exit and heat-transfer pipe inner-wall surface are tangent.

2. new and effective seawater desalination evaporators according to claim 1, it is characterized in that: being in intake chamber spatial reducing pipeline section is the bigger pipe of radius ratio heat-transfer pipe, and being in Heat Room spatial reducing pipeline section is the reducing pipe that radius from bottom to top diminishes gradually.

Images