CN107213793B - Novel solar energy decompression multiple-effect membrane distillation device - Google Patents
Novel solar energy decompression multiple-effect membrane distillation device Download PDFInfo
- Publication number
- CN107213793B CN107213793B CN201610164390.5A CN201610164390A CN107213793B CN 107213793 B CN107213793 B CN 107213793B CN 201610164390 A CN201610164390 A CN 201610164390A CN 107213793 B CN107213793 B CN 107213793B
- Authority
- CN
- China
- Prior art keywords
- water
- membrane distillation
- effect membrane
- heat exchanger
- iii
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/36—Pervaporation; Membrane distillation; Liquid permeation
- B01D61/364—Membrane distillation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/36—Pervaporation; Membrane distillation; Liquid permeation
- B01D61/366—Apparatus therefor
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
- C02F1/14—Treatment of water, waste water, or sewage by heating by distillation or evaporation using solar energy
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/447—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by membrane distillation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2311/00—Details relating to membrane separation process operations and control
- B01D2311/26—Further operations combined with membrane separation processes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/20—Controlling water pollution; Waste water treatment
- Y02A20/208—Off-grid powered water treatment
- Y02A20/212—Solar-powered wastewater sewage treatment, e.g. spray evaporation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/30—Wastewater or sewage treatment systems using renewable energies
- Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy
Abstract
The invention discloses a novel solar pressure-reducing multi-effect membrane distillation device, which aims to heat a raw material liquid by using solar energy instead of traditional electric heating as a heat source so as to achieve the purposes of saving energy and reducing consumption. Meanwhile, a set of simple Venturi system is used for replacing a vacuum pump used in the reduced-pressure multi-effect membrane distillation, so that the energy consumption in the operation process of the membrane distillation is further reduced, 100% collection of produced water is realized, and the membrane flux is improved. The application of the multi-effect membrane distillation component realizes the effective utilization of vapor phase change heat and improves the heat utilization rate. By using the novel Venturi-solar pressure reduction multi-effect membrane distillation system, the overall energy consumption and the operation cost in the membrane distillation process can be greatly reduced.
Description
Technical Field
The invention relates to a multi-effect membrane distillation device, in particular to a novel solar energy pressure reduction multi-effect membrane distillation device.
Background
The membrane distillation technology is a novel separation technology combining the traditional distillation method and the membrane technology, and can be applied to the processes of desalination, concentration and the like of seawater/brackish water/industrial wastewater. The membrane distillation separates two solutions with different temperatures by a microporous hydrophobic membrane, and the permeable component in the raw material liquid at the higher temperature side passes through a separation membrane in a gas molecular form by using the steam partial pressure difference of the permeable component at the two sides of the hydrophobic membrane as a driving force, so that mass transfer is realized; at the same time, liquids, insoluble substances, ions and the like cannot penetrate the hydrophobic membrane. The membrane distillation technology has the advantages of high desalination rate, good water quality of produced water, high water recovery rate and the like, but at present, the technology is generally in a pilot-plant research stage and has no industrial application. One of the main problems limiting the industrial application of membrane distillation is: heating the feed solution using conventional means (electrical heating) results in high energy consumption and running costs.
Solar energy is an inexhaustible and readily available renewable green energy source. With the development of solar technology, researchers have successfully combined solar energy utilization with a membrane distillation process, and a low-temperature solar heat collection device (i.e., a solar heat collection tube) is used to heat a raw material liquid in the membrane distillation process to a desired temperature. Compared with single membrane distillation, the membrane distillation process of the coupling solar energy has lower energy consumption, does not generate secondary pollution, greatly reduces the operating cost, and can realize the triple benefits of consumption reduction, environmental protection and cost saving. However, in the existing solar membrane distillation technology, under the conditions of pipeline loss and no system heat recycling, the heat loss of the whole system can reach more than 50%.
The multi-effect membrane distillation can effectively recover the phase change heat of gas/liquid, improve the utilization efficiency of heat energy and improve the water making ratio. In the process, steam generated by vaporizing permeable components in the membrane distillation assembly is used as a secondary heat source to heat the raw material liquid, so that the temperature of the raw material liquid is gradually increased; and the steam is condensed into liquid to be collected because of heat release and temperature reduction. Therefore, the energy consumption of the membrane distillation process can be effectively reduced. Depending on the specific membrane distillation process, reduced pressure/vacuum multi-effect membrane distillation, air gap multi-effect membrane distillation, air sweep multi-effect membrane distillation, roll-up multi-effect membrane distillation, etc. have also been developed.
A vacuum pump is needed in the process of reduced pressure membrane distillation, and the generated steam can penetrate through the separation membrane at a higher speed than other membrane distillation modes by utilizing the low pressure/negative pressure formed by the vacuum pump on the shell side of the membrane component, so that the membrane flux is improved; the condensed water generated after the heat release of the steam is easier to collect under the suction action of the vacuum pump. But the use of a vacuum pump increases the energy consumption of the membrane distillation process; on the other hand, part of the water vapor which is not condensed enters the pump body of the vacuum pump by the suction action of the vacuum pump, and damages the vacuum pump in the long-term operation process, thereby increasing the operation cost of the process. In addition, in the reduced pressure/vacuum multi-effect membrane distillation process, relying solely on the condensation within the membrane module itself is not sufficient to recover all of the water vapor. Therefore, an additional heat exchanger is required, and the use of the heat exchanger can increase the overall energy consumption of the membrane distillation process.
Chinese patent CN203155103U relates to a membrane module and a membrane distillation system combining solar energy. The membrane component comprises a cold working medium containing cavity with a cold wall and a hot working medium containing cavity with a membrane, and a gap is arranged between the permeation side of the membrane and the cold wall, which is equivalent to an air gap membrane distillation component. The membrane distillation device needs to use a solar power generation system, the cold working medium cavity is kept in a low-temperature state by utilizing a thermoelectric refrigeration technology, the equipment is complex and high in investment, the generated steam phase-change heat is not recycled, and the heat energy utilization efficiency is low.
Chinese patent CN104261608A discloses a solar membrane distillation seawater desalination method, which comprises a membrane distillation assembly with hollow fiber membranes and hollow fiber condenser tubes alternately woven and filled, and corresponding matching units. The design of membrane module has realized the recovery of condensation latent heat in this patent, has improved heat utilization rate. But the preparation process of the membrane component is more complicated; and after the membrane module is polluted to cause performance reduction, the staggered hollow fiber membranes and hollow fiber condenser pipes are not easy to clean and replace.
Chinese patent CN102107119A proposes a vacuum multi-effect membrane distillation apparatus and method. The device consists of a heating evaporation area, a main evaporation area and a cooling evaporation area, has higher heat recovery rate, and does not need an expensive heat pump system. However, the vacuum pump is used in the device, so that the problems of the vacuum membrane distillation process are caused, and the energy optimization effect of the multi-effect membrane distillation is weakened.
US9023211B2 relates to the use of an aspirator instead of a vacuum pump to generate vacuum pressure during vacuum membrane distillation. In this patent, the water vapor produced by membrane distillation is collected in its entirety by the suction created by the liquid flowing through the aspirator. In addition, compared with a vacuum pump, the process has lower energy consumption, and the purposes of energy conservation and consumption reduction are realized. But the technology is not applied to the solar reduced pressure multi-effect membrane distillation process at present.
Compared with the above patent, the application relates to a method for utilizing the Venturi effect in the solar reduced-pressure multi-effect membrane distillation process, and organically combines the advantages of the respective technologies. The Venturi-solar pressure reduction multi-effect membrane distillation system is designed, so that the traditional electric heating can be replaced by the solar heat collecting tube, the raw material liquid in the membrane distillation is raised to the required temperature, the consumption of electric energy is reduced, and the Venturi-solar pressure reduction multi-effect membrane distillation system is a novel green and environment-friendly technology; the system uses the reduced-pressure multi-effect membrane distillation assembly, so that the recycling of the phase change heat of the water vapor is realized, and the heat energy utilization efficiency of the process is improved; based on the suction effect generated by the Venturi effect, the vacuum pump can be replaced, the energy consumption and the operation difficulty in the membrane distillation process are further reduced, the equipment expenditure/maintenance cost is reduced, and the produced water is completely recovered.
Disclosure of Invention
The invention aims to combine the solar energy and the membrane distillation process, and heat the raw material liquid by utilizing the solar heat collecting tube instead of an electric heating mode in the traditional membrane distillation process, thereby effectively reducing the energy consumption and the operating cost of the membrane distillation.
Another object of the present invention is to recover and utilize the latent heat of condensation of water vapor based on a multi-effect membrane distillation process, and to increase the efficiency of heat energy utilization of the process.
The third purpose of the invention is to overcome the defects of the existing pressure reduction membrane distillation technology and provide a method for applying the Venturi effect to the pressure reduction multi-effect membrane distillation. The Venturi tube system is used for replacing a traditional vacuum pump, so that the water is completely recovered, and the water yield is improved; the loss of water vapor to a vacuum pump in the long-term operation process of membrane distillation is avoided; and reduces the energy consumption and the operating cost of the reduced-pressure multi-effect membrane distillation process.
In order to achieve the above purpose, the invention adopts the following technical scheme:
a novel solar reduced-pressure multi-effect membrane distillation device comprises: the H-type multi-effect membrane distillation component 7, the Venturi tube system, the heat exchange system, the solar heat collection system and the raw water tank 1;
the H-type multi-effect membrane distillation assembly 7 comprises a cold water inlet 47, a cold water outlet 45, a hot water inlet 44, a hot water outlet 46, an H-type multi-effect membrane distillation assembly produced water outlet I48 and an H-type multi-effect membrane distillation assembly produced water outlet II 49;
the venturi system includes: the valve III 18, the Venturi tube 21, the water production tank 25, the diaphragm pump III 24, the rotor flow meter II 23 and the heat exchanger III 22;
a cold water inlet 47 of the H-type multi-effect membrane distillation assembly is connected with a water outlet of the raw water tank 1, a cold water outlet 45 of the H-type multi-effect membrane distillation assembly is connected with a water inlet of a heat exchange system, a hot water inlet 44 of the H-type multi-effect membrane distillation assembly is connected with a water outlet of the heat exchange system, and a hot water outlet 46 of the H-type multi-effect membrane distillation assembly is connected; the water outlet of the heat exchanger III 22 is connected with the water inlet of the raw water tank 1;
the H-type multi-effect membrane distillation assembly water production outlet I48 and the H-type multi-effect membrane distillation assembly water production outlet II 49 are both connected with a valve III 18 of the Venturi tube system;
the middle part of the solar heat collection system is connected with the upper part of the heat exchange system through a valve VI (29), and the bottom of the solar heat collection system is connected with the bottom of the heat exchange system.
On the basis of the scheme, the solar heat collection system comprises: a solar thermal collector and a water storage system;
the solar collector comprises: a heat collecting pipe 41 and a heat exchanger II 38;
the water storage system includes: a water storage tank 35, a rotor flow meter III 34, a diaphragm pump V33, a three-way valve 32 and a diaphragm pump VI 31.
A water outlet at the lower end of the water storage tank 35 is provided with a three-way valve 32, the left side of the three-way valve 32 is connected with the bottom of the heat exchange system, and the middle of the three-way valve is provided with a diaphragm pump VI 31; the right side of the three-way valve 32 is connected with a water inlet of a heat exchanger II 38, a rotameter III 34 and a diaphragm pump V33 are arranged in the middle, a water inlet at the upper end of the water storage tank 35 is connected with a water outlet of the heat exchanger II 38, and a temperature gauge VI 36 is arranged in the middle.
And a diaphragm pump IV 40 and a temperature gauge VIII 39 are arranged between the heat exchanger II 38 and the bottom outlet of the heat collecting pipe 41, and a temperature gauge VII 37 is arranged between the heat exchanger II 38 and the top inlet of the heat collecting pipe 41.
On the basis of the scheme, the heat collecting pipe 41 is placed at an angle of 45 degrees and is connected with the heat exchanger II 38.
On the basis of the scheme, a condensation/temperature-increasing region 9 is arranged between a cold water inlet 47 and a cold water outlet 45 of the H-type multi-effect membrane distillation assembly, and an evaporation region 8 is arranged between a hot water inlet 44 and a hot water outlet 46.
On the basis of the scheme, the water production outlet I48 of the H-type multi-effect membrane distillation assembly is positioned at the lower part of the evaporation zone 8, and the water production outlet II 49 of the H-type multi-effect membrane distillation assembly is positioned at the lower part of the condensation/warming zone 9.
On the basis of the above solution, the venturi tube 21 comprises a venturi tube water inlet 50, a water vapour/water production inlet 51 and a venturi tube water outlet 52.
On the basis of the scheme, in the Venturi tube system, a steam/water production inlet 51 is connected with a valve III 18, a Venturi tube water inlet 50 is connected with a heat exchanger III 22, and a Venturi tube water outlet 52 is connected with a water inlet of a water production tank 25; and the rotameter II 23 and the diaphragm pump III 24 are positioned between the heat exchanger III 22 and the water outlet of the water production tank 25.
On the basis of the scheme, a pressure gauge II 20 is arranged between the Venturi tube water outlet 52 and the water inlet of the water production tank 25, and a pressure gauge II 19 is arranged between the Venturi tube water inlet 50 and the heat exchanger III 22.
On the basis of the scheme, a diaphragm pump I2, a rotor flow meter I3, a pressure gauge I4, a thermometer I5 and a valve I6 are arranged between a cold water inlet 47 of the H-type multi-effect membrane distillation assembly and a water outlet of the raw water tank 1.
On the basis of the scheme, the heat exchange system comprises a heat exchanger I11, a diaphragm pump II 12 and a hot water tank 13.
On the basis of the scheme, a cold water outlet 45 of the H-type multi-effect membrane distillation assembly is connected with a water inlet of a heat exchanger I11, and a temperature table II 10 is arranged between the cold water outlet 45 and the heat exchanger I11.
On the basis of the scheme, the hot water inlet 44 is connected with the water outlet of the heat exchanger I11, and a temperature gauge III 15 and a valve II 14 are arranged between the hot water inlet and the water outlet.
On the basis of the scheme, a temperature gauge IV 17 is arranged between the hot water outlet 46 and the water inlet of the heat exchanger III 22.
On the basis of the scheme, a temperature gauge V26, a filtering device 27 and a valve V28 are arranged between the water outlet of the heat exchanger III 22 and the water inlet of the raw water tank 1.
On the basis of the scheme, a valve IV 16 is arranged between the water outlet I48 of the H-type multi-effect membrane distillation assembly and the valve III 18.
On the basis of the scheme, the middle inlet 53 of the water storage tank 35 of the solar heat collection system is connected with the floating ball valve 30 in the hot water tank 13 of the heat exchange system through a valve VI 29.
On the basis of the scheme, the diaphragm pump VI 31 of the solar heat collection system is connected with the hot water tank bottom inlet 54 of the hot water tank 13 of the heat exchange system.
Has the advantages that:
compared with the existing solar membrane distillation system, the invention has the following advantages:
(1) the latent heat of condensation of the water vapor can be effectively utilized, and the heat energy utilization efficiency is improved;
(2) the Venturi tube is used for replacing a traditional vacuum pump, so that energy consumption generated in the vacuum pumping process is reduced;
(3) the water can be completely collected, and the water yield is improved;
(4) due to the existence of the filtering module in the system, the membrane pollution degree in the multi-effect membrane distillation process is lighter, and the continuous and stable running time of the system is prolonged;
(5) the existing solar membrane distillation system is optimized and simplified, and the construction cost of the device, the whole energy consumption of the process and the operation cost are reduced.
Drawings
FIG. 1 is a schematic diagram of a Venturi-solar vacuum multi-effect membrane distillation device;
FIG. 2 is a schematic diagram of an H-type reduced pressure multi-effect membrane distillation module;
figure 3 is a schematic diagram of a venturi.
The thick solid arrows in each figure represent the direction of flow of the liquid and the dashed arrows represent the direction of flow of the steam and water produced.
In the figure, 1, a raw water tank, 2, diaphragm pumps I, 3, rotameters I, 4, pressure gauges I, 5, temperature gauges I, 6, valves I, 7, an H type multi-effect membrane distillation component, 8, an evaporation area, 9, a condensation/temperature rise area, 10, temperature gauges II, 11, heat exchangers I, 12, diaphragm pumps II, 13, a hot water tank, 14, valves II, 15, temperature gauges III, 16, valves IV, 17, temperature gauges IV, 18, valves III, 19, pressure gauges II, 20, pressure gauges III, 21, venturi tubes, 22, heat exchangers III, 23, rotameters II, 24, diaphragm pumps III, 25, a water production tank, 26, temperature gauges V, 27, a filtering device, 28, valves V, 29, valves VI, 30, a floating ball valve, 31, diaphragm pumps VI, 32, a three-way valve, 33, diaphragm pumps III, 34, rotameters, 35, a water storage tank, 36 and temperature gauges VI, 37. the system comprises a temperature meter VII, 38, heat exchangers II, 39, temperature meters VIII, 40, diaphragm pumps IV, 41, heat collecting pipes, 42, sunlight, 43, water vapor, 44, a hot water inlet, 45, a cold water outlet, 46, a hot water outlet, 47, a cold water inlet, 48, an H-type multi-effect membrane distillation assembly water production outlet I, 49, an H-type multi-effect membrane distillation assembly water production outlet II, 50, a venturi tube water inlet, 51, a water vapor/water production inlet, 52 and a venturi tube water outlet. 53. The middle inlet of the water storage tank, 54, the bottom inlet of the hot water tank
Detailed Description
The invention is further described with reference to the accompanying drawings and the embodiments.
Figure 1 presents a schematic view of a venturi-solar reduced pressure multi-effect membrane distillation apparatus. In the figure, raw material liquid is controlled in flow rate by a diaphragm pump I2 and a rotor flow meter I3 in a raw water tank 1 and enters a condensation zone 9 of an H-type multi-effect membrane distillation assembly. The stock solution passes through the dense high-molecular hollow tubule in the condensation zone 9 from bottom to top. The stock solution is gradually heated in the hollow tubule by latent heat released by the condensation of high-temperature steam on the surface of the tubule. The stock solution heated to a certain temperature flows out of a condensation zone 9 of the H-type multi-effect membrane distillation assembly, and is further heated to a required temperature through hot water in a heat exchanger I11 before entering an evaporation zone 8 of the H-type multi-effect membrane distillation assembly.
The hot water in the heat exchanger I11 comes from a solar heat collection system. The solar light 42 is converted into heat by the solar heat collecting pipe 41. After being heated by the heat, the water in the heat collecting pipe 41 exchanges heat with the water in the water storage tank 35 through the heat exchanger II 38. The water from the water storage tank 35 can exchange heat with the hot water in the heat collecting pipe 41 and enter the hot water tank 13 through a three-way valve 32. The water level in the hot water tank 13 is controlled by a level controller and a valve VI 29, and when the liquid level is too high, the valve VI 29 is automatically opened to allow the excess water to flow back to the water storage tank 35 from the hot water tank 13.
The raw material liquid heated to a predetermined temperature passes through the microporous hollow fiber membranes in the evaporation zone 8 from top to bottom. The water vapor 43 permeates the micropores on the membrane surface, enters the shell side of the H-type multi-effect membrane distillation assembly 7 under the suction effect generated by the venturi tube system, and then enters the condensation zone 9 of the H-type multi-effect membrane distillation assembly. The water vapor 43 is condensed on the surface of the high molecular hollow tubule with lower temperature, and flows down along the tubule and flows out at the bottom of the H-type multi-effect membrane distillation component 7. The water generating tank 25 stores a certain amount of purified water in advance, the flow rate of the purified water is controlled by the diaphragm pump III 24 and the rotor flow meter II 23, the purified water flows through the heat exchanger III 22, and then a pressure difference is formed when the purified water flows through the venturi tube 21, so that a suction force is generated. The produced water in the H-type multi-effect membrane distillation module 7 and the water vapor 43 which is not fully condensed to form liquid water are completely carried away by the water flow in the venturi tube 21 and collected in the water production tank 25. The temperature of the stock solution gradually decreases while the stock solution flows in the evaporation zone 8. The produced water in the heat exchanger III 22 is continuously cooled to the room temperature after flowing out of the H-type multi-effect membrane distillation assembly 7, insoluble substances which may be separated out in the process of continuously evaporating and changing the temperature of the raw water are removed through a filtering device 27, and finally, the insoluble substances flow back to the raw water tank 1.
Figure 2 shows a schematic diagram of a multiple effect membrane distillation module of the H-type. The multiple effect membrane distillation module 7 of the H-type in the figure comprises a condensation/warming zone 9 and an evaporation zone 8. In the condensation/warming zone 9, the hollow fine polymer tubes used are arranged in parallel without contact. In the evaporation zone 8, microporous hollow fiber membranes made of a polymer material are also arranged in parallel without contact with each other. The evaporation zone 8 and the condensation zone 9 are connected by an H-shaped glass shell with a through middle part. The evaporation zone 8 is coated with a heat insulating material. The water outlet of the H-type multi-effect membrane distillation component is arranged at the lower end of the component. The water production outlet I48 is used for discharging the water which is possibly accumulated in the evaporation zone 8; and the water production outlet II 49 is used for discharging the water produced in the condensation area 9 after the heat is released by the condensation of the water vapor 43.
Figure 3 shows a schematic diagram of a venturi tube. Including a venturi water inlet 50, a water vapor/water production inlet 51 and a venturi water outlet 52. The purified water in the water generating tank 25 enters from the venturi tube water inlet 50, and the flow velocity is increased along with the gradual reduction of the inner section of the venturi tube. A vacuum is created at the steam/product water inlet 51 so that the product water and steam 43 in the H-type multi-effect membrane distillation module 7 are drawn into the venturi tube 21 and flow back into the product water tank 25 with the water flow.
The operation process comprises the following steps:
(1) checking to ensure that the connection of each component is correct and tight.
(2) The solar heat collecting device is a U-shaped tubular vacuum tube type solar heater with a glass metal structure, and the lighting area is 4m2The heat collecting pipes 41 are installed in the north-south direction, and the inclination angle is 45 degrees. And (3) starting a diaphragm pump IV 40 in the solar heat collecting system, opening the right part of a three-way valve 32 at a water outlet at the lower end of a water storage tank 35 when the temperature of hot water in the heat collecting system reaches above 70 ℃, starting a diaphragm pump V33, and controlling the flow rate of water through a rotameter III 34. The water in the water storage tank 35 exchanges heat with the water in the solar heat collection system at the heat exchanger II 38. The heat exchanger II 38 is a flat plate heat exchanger with a heat exchange area of 1.6m2. The water storage tank 35 is a closed pressure-resistant water tank with a capacity of 150L. When the temperature of water in the water storage tank 35 reaches above 60 ℃, the left part of the three-way valve 32 is opened, and water enters the hot water tank 13 in the membrane distillation system through the diaphragm pump VI 31. The amount of water in the hot water tank 13 is about 70L, and the water level thereof is controlled by a level controller. When the liquid level reaches a predetermined level, the valve vi 29, which is in communication with the ball float valve 30, automatically opens and excess water will flow back into the water storage tank 35.
(3) Diaphragm pumps I2 and II 12 are started, a valve I6, a valve II 14 and a valve V28 are opened, and the flow rate of raw material liquid in the raw water tank 1 is controlled through a rotor flow meter I3. The pressure gauge I4 and the temperature gauge I5 are used for monitoring the temperature and the pressure of the raw material liquid before entering the heating area 9 of the H-type multi-effect membrane distillation assembly. The temperature meter II 10 and the temperature meter III 15 are respectively used for monitoring the temperature of the raw material liquid after passing through the temperature increasing zone 9 and the temperature of the raw material liquid before entering the evaporation zone 8 of the H-type multi-effect membrane distillation assembly after heat exchange is carried out on the raw material liquid through the heat exchanger I11. The heat exchanger I11 is a coil type heat exchanger. The temperature table IV 17 is used for monitoring the temperature of the raw material liquid after flowing out of the evaporation zone 8 of the H-type multi-effect membrane distillation assembly.
The heating area 9 of the H-type multi-effect membrane distillation assembly adopts a polypropylene (PP) heat exchange tubule, the inner diameter is 0.4mm, and the outer diameter is 0.7 mm; the evaporation area 8 of the H-type multi-effect membrane distillation component adopts a polypropylene (PP) hollow fiber hydrophobic membrane, the inner diameter is 1.8mm, the outer diameter is 2.7mm, the porosity is 73.9%, the average pore diameter is 0.238 mu m, and the contact angle of the membrane surface is 148 degrees; the shell material of the H-type multi-effect membrane distillation component 7 is glass, the length is 400mm, and the total area of the inner membranes of the H-type multi-effect membrane distillation component 7 is 0.16m2. The H-type multi-effect membrane distillation component 7 is externally wrapped by heat-preservation sponge. The raw material liquid flows out of the H-type multi-effect membrane distillation membrane component 7 and then enters the heat exchanger III 22. The heat exchanger III 22 is a coil heat exchanger.
Finally, the raw material liquid passes through the filter 27 and then flows back to the raw water tank 1. The pore size of the filter 27 is 0.5. mu.m. After the system stably operates for a period of time, the diaphragm pump III 24 is started, the flow rate is controlled through the rotor flow meter II 23, and cold water in the water production tank 25 is conveyed to the heat exchanger III 22. The water generating tank 25 is a closed pressure-resistant water tank, and 70L of clean cold water is filled in the water generating tank. Cold water enters the Venturi tube 21 after exchanging heat with the raw material liquid through the heat exchanger III 22. The venturi tube 21 is made of aluminum alloy and has a length of 150mm, a diameter of 15mm at a water inlet 50 of the venturi tube, a diameter of 10mm at a steam/water inlet 51, and a diameter of 25mm at a water outlet 52 of the venturi tube. The cold water flowing through the venturi tube 21 creates a low pressure at the steam/product water inlet 51, thereby creating a suction force, allowing the steam 43 and product water from the H-type multi-effect membrane distillation module 7 to be drawn into the venturi tube 21 and carried back to the product water tank 25 for collection. Valve iii 18 is opened immediately after the venturi system has started to operate. If after a period of operation there is a build up of liquid water in the evaporation zone 8, valve IV 16 can be opened to collect the water produced in this zone.
(4) The membrane distillation unit was shut down. The membrane pump i 2 is closed, followed by the three-way valve 32 and the membrane pump v 33 and the membrane pump vi 31. And when the membrane distillation system operates to the temperature of lower than 45 ℃, closing the membrane pump I2, the valve I6, the valve II 14 and the valve V28. Then when the H type multi-effect membrane distillation assembly 7 does not produce water any more, the diaphragm pump III 24 is closed, and the valve II 14 and the valve III 18 are closed.
The first embodiment is as follows:
most areas in China belong to 3 types and more than 3 types of sunshine areas (areas where solar energy can be used), and the annual sunshine time is more than 2000 hours. Therefore, the Venturi-solar pressure reduction multi-effect membrane distillation system has a wide application prospect, and particularly can be used for preparing drinking water and domestic water in areas with shortage of fresh water resources and abundant brackish water.
In a certain city in a 3-class sunshine area in China, under the typical condition of sunny weather in summer. The solar radiation intensity gradually increases from 8 am, reaches the strongest value from 12 to 14 am, then gradually becomes weaker, and the average total irradiance exceeds 900 W.m2The total solar radiation amount can reach 20 MJ.m2·d-1. At this time, the daily average efficiency and instantaneous efficiency of the evacuated tube collector were approximately 45% and 70%, respectively. The outdoor ambient temperature is between 29 and 35 ℃ and reaches the highest in the noon.
The water temperatures in the water storage tank 35 and the hot water tank 13 change along with the change of the solar radiation intensity, and can reach more than 80 ℃ in the middle of the day. The use concentration is 35 g.L-1The NaCl salt solution of (2) was used as a raw material solution, and the flow rate was controlled by a rotameter to 120 L.h-1The flow rate of hot water in the hot water tank 13 is 600 L.h-1The temperature of the raw material liquid is controlled to be about 70 ℃ before entering the evaporation zone 8, and the flow rate of cold water in a Venturi tube system (cold side) is controlled to be 360 L.h-1The pressure generated at the steam inlet 51 was 10kPa, and the continuous operation was carried out for 5 hours, and the maximum membrane flux obtained was 11L m-2·h-1The conductivity of the produced water is 10 mu S cm-1Left and right, high salt rejectionAt a rate of 99.5%.
Note that:
(1) after the membrane distillation device is operated for a period of time, when the conductivity of the produced water is higher than 100 mu S-cm-1When the H-type multi-effect membrane distillation assembly 7 needs to be cleaned. Hydrochloric acid solution with pH of 2.5 and NaOH solution with pH of 11.5 were prepared, and the H-type multi-effect membrane distillation module was cleaned for 730 minutes, respectively. Valve I6, valve II 14 and valve V28 are opened, keeping all other valves closed. After the diaphragm pump I2 is started, the flow speed is controlled through the rotameter, so that the H-type multi-effect membrane distillation assembly 7 is in a dynamic cleaning process with constantly changing flow speed. And then, cleaning with clear water until the pH value of the cleaning solution is restored to about 7.
(2) After the membrane distillation device is operated for a period of time, the water amount in the raw water tank 1 is reduced, the salt concentration is increased, the temperature is increased, and the raw water tank 1 needs to be supplemented with water in a manual mode.
(3) After the membrane distillation device is operated for a period of time, the water amount in the water production tank 25 gradually increases, the temperature rises, part of the produced water needs to be removed manually, and tap water is used for supplementing water to the water production tank 25.
(4) The water temperature change in the solar heat collection system is not synchronized with the change of the solar radiation intensity, but has a lag time.
(5) Attention is paid to heat preservation of the H-type multi-effect membrane distillation assembly 7, the solar heat collection device, the pipeline, the water tank and the like, and heat loss is reduced.
(6) When the pressure drop is found to be large and the flow rate of the raw material liquid is continuously decreased, the insoluble matter accumulated in the filter 27 increases, and the filter 27 needs to be cleaned and replaced.
The second embodiment:
in a certain city in 3-class sunshine area of China, under the typical condition of cloudy days in summer. The solar radiation intensity is very low, and the total solar radiation amount is less than 8 MJ.m2·d-1. The outdoor environment temperature is between 30 and 34 ℃.
The temperature in the water storage tank 35 and the hot water tank 13 changes along with the intensity of solar radiation, and the temperature range is between 50 and 60 ℃. The use concentration is 35 g.L-1NaCl salt solution of (2)The flow rate of the solution as a raw material solution was controlled to 120 L.h by a rotameter-1The flow rate of hot water in the hot water tank 13 is 600 L.h-1The temperature of the raw material liquid is 54 ℃ before entering the evaporation zone 8, and the flow rate of the cold water in a Venturi tube system (cold side) is controlled to be 360 L.h-1The pressure generated at the steam inlet 51 was 10kPa, and the continuous operation was carried out for 6 hours, whereby the maximum membrane flux was obtained at only 4 L.m-2·h-1The conductivity of the produced water is 6 mu S cm-1And the salt rejection rate is more than 99.9 percent. Therefore, cloudy days are not suitable for the operation of solar membrane distillation systems.
Those not described in detail in this specification are within the skill of the art.
Claims (10)
1. A novel solar reduced-pressure multi-effect membrane distillation device is characterized by comprising: the device comprises an H-type multi-effect membrane distillation assembly (7), a Venturi tube system, a heat exchange system, a solar heat collection system and a raw water tank (1);
the H-type multi-effect membrane distillation assembly (7) comprises a cold water inlet (47), a cold water outlet (45), a hot water inlet (44), a hot water outlet (46), an H-type multi-effect membrane distillation assembly water production outlet I (48) and an H-type multi-effect membrane distillation assembly water production outlet II (49);
the venturi system includes: a valve III (18), a Venturi tube (21), a water production tank (25), a diaphragm pump III (24), a rotor flow meter II (23) and a heat exchanger III (22);
a cold water inlet (47) of the H-type multi-effect membrane distillation assembly is connected with a water outlet of the raw water tank (1), a cold water outlet (45) is connected with a water inlet of the heat exchange system, a hot water inlet (44) is connected with a water outlet of the heat exchange system, and a hot water outlet (46) is connected with a water inlet of the heat exchanger III (22); the water outlet of the heat exchanger III (22) is connected with the water inlet of the raw water tank (1);
the H-type multi-effect membrane distillation assembly water production outlet I (48) and the H-type multi-effect membrane distillation assembly water production outlet II (49) are both connected with a valve III (18) of the Venturi tube system;
the middle part of the solar heat collection system is connected with the upper part of the heat exchange system through a valve VI (29), and the bottom of the solar heat collection system is connected with the bottom of the heat exchange system;
the solar energy collection system comprises: a solar thermal collector and a water storage system;
the solar collector comprises: a heat collecting pipe (41) and a heat exchanger II (38);
the water storage system includes: a water storage tank (35), a rotameter III (34), a diaphragm pump V (33), a three-way valve (32) and a diaphragm pump VI (31);
a water outlet at the lower end of the water storage tank (35) is provided with a three-way valve (32), the left side of the three-way valve (32) is connected with the bottom of the heat exchange system, and the middle of the three-way valve is provided with a diaphragm pump VI (31); the right side of the three-way valve (32) is connected with a water inlet of a heat exchanger II (38), a rotameter III (34) and a diaphragm pump V (33) are arranged in the middle, a water inlet at the upper end of a water storage tank (35) is connected with a water outlet of the heat exchanger II (38), and a thermometer VI (36) is arranged in the middle;
a diaphragm pump IV (40) and a thermometer VIII (39) are arranged between the heat exchanger II (38) and the bottom outlet of the heat collecting pipe (41), and a thermometer VII (37) is arranged between the heat exchanger II (38) and the top inlet of the heat collecting pipe (41);
a condensation/temperature-increasing region (9) is arranged between a cold water inlet (47) and a cold water outlet (45) of the H-type multi-effect membrane distillation assembly, and an evaporation region (8) is arranged between a hot water inlet (44) and a hot water outlet (46);
the H-type multi-effect membrane distillation assembly water production outlet I (48) is positioned at the lower part of the evaporation area (8), and the H-type multi-effect membrane distillation assembly water production outlet II (49) is positioned at the lower part of the condensation/temperature increase area (9);
the venturi tube (21) comprises a venturi tube water inlet (50), a steam/water production inlet (51) and a venturi tube water outlet (52);
in the Venturi tube system, a steam/water production inlet (51) is connected with a valve III (18), a Venturi tube water inlet (50) is connected with a heat exchanger III (22), and a Venturi tube water outlet (52) is connected with a water inlet of a water production tank (25); the rotor flow meter II (23) and the diaphragm pump III (24) are positioned between the heat exchanger III (22) and a water outlet of the water production tank (25);
a pressure gauge III (20) is arranged between the water outlet (52) of the Venturi tube and the water inlet of the water production tank (25), and a pressure gauge II (19) is arranged between the water inlet (50) of the Venturi tube and the heat exchanger III (22);
and a thermometer V (26), a filtering device (27) and a valve V (28) are arranged between the water outlet of the heat exchanger III (22) and the water inlet of the raw water tank (1).
2. The novel solar energy pressure reduction multi-effect membrane distillation device as claimed in claim 1, wherein the heat collecting tube (41) is arranged at an angle of 45 degrees and is connected with the heat exchanger II (38).
3. The novel solar energy pressure reduction multi-effect membrane distillation device as claimed in claim 1, wherein a diaphragm pump I (2), a rotor flow meter I (3), a pressure gauge I (4), a thermometer I (5) and a valve I (6) are arranged between a cold water inlet (47) of the H-type multi-effect membrane distillation assembly and a water outlet of the raw water tank (1).
4. The novel solar reduced-pressure multi-effect membrane distillation device as claimed in claim 1, wherein the heat exchange system comprises a heat exchanger I (11), a diaphragm pump II (12) and a hot water tank (13).
5. The novel solar energy pressure reduction multi-effect membrane distillation device as claimed in claim 4, wherein the cold water outlet (45) of the H-type multi-effect membrane distillation assembly is connected with the water inlet of the heat exchanger I (11), and a temperature gauge II (10) is arranged between the cold water outlet and the heat exchanger I.
6. The novel solar reduced-pressure multi-effect membrane distillation device as claimed in claim 5, wherein the hot water inlet (44) is connected with the water outlet of the heat exchanger I (11), and a temperature gauge III (15) and a valve II (14) are arranged between the hot water inlet and the heat exchanger I.
7. The novel solar reduced-pressure multi-effect membrane distillation device as claimed in claim 1, wherein a temperature gauge IV (17) is arranged between the hot water outlet (46) and the water inlet of the heat exchanger III (22).
8. The novel solar energy pressure reduction multi-effect membrane distillation device as claimed in claim 1, wherein a valve IV (16) is arranged between the water outlet I (48) of the H-type multi-effect membrane distillation assembly and the valve III (18).
9. The novel solar reduced-pressure multi-effect membrane distillation device as claimed in claim 1, wherein the central part of the solar heat collection system is a water storage tank central inlet (53) of a water storage tank (35); the bottom of the solar heat collection system is a water outlet of a diaphragm pump VI (31).
10. The new solar energy reduced pressure multi-effect membrane distillation plant according to claim 4, characterized in that the upper part of the heat exchange system is a float ball valve (30) in the hot water tank (13);
the bottom of the heat exchange system is a hot water tank bottom inlet (54) of the hot water tank (13).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610164390.5A CN107213793B (en) | 2016-03-22 | 2016-03-22 | Novel solar energy decompression multiple-effect membrane distillation device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610164390.5A CN107213793B (en) | 2016-03-22 | 2016-03-22 | Novel solar energy decompression multiple-effect membrane distillation device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107213793A CN107213793A (en) | 2017-09-29 |
| CN107213793B true CN107213793B (en) | 2020-05-12 |
Family
ID=59927693
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610164390.5A Active CN107213793B (en) | 2016-03-22 | 2016-03-22 | Novel solar energy decompression multiple-effect membrane distillation device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107213793B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107935119B (en) * | 2017-12-22 | 2023-09-12 | 北京中新国能环保科技有限公司 | Device, system and method for treating desulfurization wastewater by photo-thermal decompression multi-effect membrane distillation |
| CN110496537A (en) * | 2018-05-18 | 2019-11-26 | 中国石油化工股份有限公司 | A kind of solar heat pump membrane distillation system |
| ES2805549A1 (en) * | 2019-08-12 | 2021-02-12 | Lopez Jose Franco | Method to boil salt water, using solar thermal energy and vacuum techniques. (Machine-translation by Google Translate, not legally binding) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102795686A (en) * | 2012-08-20 | 2012-11-28 | 杭州电子科技大学 | Device for seawater desalination based on solar energy heat collection |
| CN102826700A (en) * | 2012-08-13 | 2012-12-19 | 浙江东大环境工程有限公司 | Solar membrane distillation seawater desalination plant for sea island |
| CN103316588A (en) * | 2012-03-20 | 2013-09-25 | 天津工业大学 | Multiple-effect membrane distillation device and method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8512567B2 (en) * | 2010-08-31 | 2013-08-20 | General Electric Company | Vapor compression membrane distillation system and method |
| SG11201403242VA (en) * | 2011-12-15 | 2014-07-30 | Masdar Inst Of Science And Technology | Vacuum membrane distillation (vmd) using aspirator to generate vacuum pressure |
-
2016
- 2016-03-22 CN CN201610164390.5A patent/CN107213793B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103316588A (en) * | 2012-03-20 | 2013-09-25 | 天津工业大学 | Multiple-effect membrane distillation device and method |
| CN102826700A (en) * | 2012-08-13 | 2012-12-19 | 浙江东大环境工程有限公司 | Solar membrane distillation seawater desalination plant for sea island |
| CN102795686A (en) * | 2012-08-20 | 2012-11-28 | 杭州电子科技大学 | Device for seawater desalination based on solar energy heat collection |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107213793A (en) | 2017-09-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108622982B (en) | Solar membrane distillation system combined with heat pump technology | |
| CN101475233B (en) | Vacuum distillation apparatus and method for desalting seawater and bitter-salt water by simply using solar energy | |
| CN109626471A (en) | In conjunction with the membrane distillation water processing system and method for solar concentrating photovoltaic photothermal technique | |
| CN101693559A (en) | Horizontal solar membrane distiller for vacuum and direct contact | |
| CN211595081U (en) | Sea water desalting device by liquid gravity distillation method | |
| CN204873910U (en) | Solar seawater desalination device based on extinction boiling | |
| CN107720863A (en) | A kind of groove type solar sea water desalinating unit based on film distillation | |
| CN109734240A (en) | A kind of seawater desalination system and desalination method | |
| CN107213793B (en) | Novel solar energy decompression multiple-effect membrane distillation device | |
| CN106745428A (en) | A kind of heat collection type solar multistage flash evaporation seawater desalting device and method | |
| CN102225787A (en) | Composite solar seawater desalination device and method | |
| CN101205087A (en) | Highly effective sea-water brackish water distillatory using renewable energy | |
| CN101117246A (en) | Integral solar energy sea water desalination production apparatus | |
| CN110526317B (en) | Solar seawater desalination device | |
| CN103626249A (en) | Sea water desalting device and method for solar photovoltaic semiconductor refrigeration | |
| CN111960494A (en) | CPC-based tracking-free light-gathering heat-collecting desalination system | |
| CN102249356B (en) | Hot water pure water coproduction device by solar energy | |
| CN103626247A (en) | Solar sea water evaporator | |
| CN108619914B (en) | Membrane distillation system using solar heat pump | |
| CN111111451B (en) | Reduced pressure multi-effect membrane distillation method and device thereof | |
| CN102003797A (en) | Device for heating water for life and preparing fresh drinking water by comprehensively utilizing solar energy | |
| CN201864592U (en) | Full-automatic solar seawater desalination device | |
| CN207632539U (en) | A kind of groove type solar desalination plant based on film distillation | |
| CN108622983B (en) | Novel membrane distillation device of coupling heat recovery system | |
| CN108619915B (en) | Air source type heat pump solar membrane distillation composite system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |