CN112239249B - Reverse osmosis sea water desalination system based on electric non-uniform concentration field - Google Patents

Abstract

The invention discloses a reverse osmosis seawater desalination system based on an electro-induced non-uniform concentration field, which has the advantages of low cost, high performance coefficient and simple structure. The reverse osmosis seawater desalination system based on the electro-induced non-uniform concentration field comprises a desalination chamber (1), a fresh water pond (2) and a concentrated water pond (3), wherein a brine inlet (11) of the desalination chamber is connected with an external brine source, a fresh water outlet (12) of the desalination chamber is connected with a fresh water inlet (21) of the fresh water pond (2), and a concentrated water outlet (13) of the desalination chamber is connected with a concentrated water inlet (31) of the concentrated water pond (3); the device also comprises a non-uniform concentration field desalination function unit; the non-uniform concentration field desalination functional unit comprises at least one electrode pair (101) and a reverse osmosis membrane (102); the electrode pair (101) is arranged in the desalination chamber (1), and the reverse osmosis membrane (102) is arranged at the fresh water outlet (12) of the desalination chamber.

Description

Reverse osmosis seawater desalination system based on electro-inhomogeneous concentration field

technical field

The invention belongs to the technical field of seawater desalination equipment, in particular to a reverse osmosis seawater desalination system based on an electrically inhomogeneous concentration field.

Background technique

Due to population growth and human waste and pollution of water resources, the crisis of fresh water resources is intensifying. According to expert estimates, by 2025, nearly half of the world's population will face severe water shortages. Among the total water volume of about 1.45 billion cubic meters on the earth, the fresh water resources directly usable by human beings account for only 0.26%, while the seawater accounts for 97.5%. The abundant seawater (salt water) is desalinated and becomes usable fresh water. It is a reliable and important way to solve the problem of insufficient water resources.

Among many seawater desalination technologies, the reverse osmosis seawater desalination technology based on the principle of reverse osmosis has many advantages such as high efficiency, low energy consumption, compact and beautiful equipment, etc., and is considered to be the leading technology in the seawater desalination market. Taking my country as an example, as of the end of 2015, there were 106 projects applying reverse osmosis technology nationwide, with a water production scale of 654,500 t/d, accounting for 64.88% of the total national water production scale.

In the natural state, when salt water and fresh water are separated by a semi-permeable membrane (reverse osmosis membrane) that only water molecules can pass through but solute (salt) molecules cannot pass through, the water molecules on the fresh water side will flow to the salt water side, reaching After the equilibrium state, the liquid level on the brine side is higher than that on the fresh water side, and the pressure difference formed by this liquid level difference is called osmotic pressure. When a pressure exceeding the osmotic pressure is applied on the salt water side, the water molecules in the salt water will flow to the fresh water side, and this process is called reverse osmosis. The essence of osmotic pressure actually reflects the attraction of solute molecules to water molecules in salt water: for pure water, water molecules can pass through the reverse osmosis membrane freely; for salt water, solute molecules will have a certain attraction to water molecules, resulting in not only solute Molecules cannot pass through the reverse osmosis membrane, and the water molecules attracted by it cannot freely pass through the reverse osmosis membrane. The macroscopic manifestation is osmotic pressure. For salt water, if the water molecules in it can pass through the reverse osmosis membrane, it can only be realized by external pressure. The reverse osmosis seawater desalination is to use this principle to realize the production of fresh water. The existing reverse osmosis seawater desalination The technology is to use a high-pressure pump to pressurize the brine and transport it to the reverse osmosis membrane module to achieve reverse osmosis, which is used to produce fresh water.

The problem existing in the prior art is: in order to use the reverse osmosis membrane to desalinate the brine, the brine source must be connected with the high-pressure pump, and the high-pressure pump is used to add the brine side to a very high pressure, which will consume huge energy; the high-pressure pump produces The high-pressure liquid will cause damage to the reverse osmosis membrane and cause the membrane to rupture; the high-pressure pump is expensive, and many costs such as pretreatment and capital construction have increased the desalination cost of the reverse osmosis technology; the operation and maintenance of the high-pressure pump is difficult and the system structure is complex. .

Contents of the invention

The object of the present invention is to provide a reverse osmosis seawater desalination system based on the electro-inhomogeneous concentration field, which has low cost, high coefficient of performance and simple structure.

The technical solution that realizes the object of the present invention is:

A reverse osmosis seawater desalination system based on an electro-induced non-uniform concentration field, comprising a desalination chamber 1, a fresh water pool 2, and a concentrated water pool 3, the salt water inlet 11 of the desalination chamber is connected to an external salt water source, and the fresh water outlet 12 of the desalination chamber is connected to the fresh water pool 2 The fresh water inlet 21 is connected, the concentrated water outlet 13 of the desalination chamber is connected with the concentrated water tank 3 concentrated water inlet 31; it also includes a non-uniform concentration field desalination functional unit; the non-uniform concentration field desalination functional unit includes at least one electrode pair 101 and reverse osmosis Membrane 102; the electrode pair 101 is placed in the desalination chamber 1, and the reverse osmosis membrane 102 is placed at the fresh water outlet 12 of the desalination chamber.

Compared with the prior art, the present invention has the remarkable advantages of:

1. Low cost and high coefficient of performance: the present invention uses an electro-inhomogeneous concentration field to desalinate reverse osmosis brine, and the electrode generates an electric field to attract solute molecules anions and cations to the surface of the electrode and near the electrode, resulting in uneven concentration in the desalination chamber The area where the concentration of salt water is as low as 0 can be regarded as a fresh water area. There is no osmotic pressure in this area, and water molecules can freely pass through the reverse osmosis membrane, which has the effect of separating salt solute molecules from water molecules. In this process, there is no need for a high-pressure water pump to pressurize the brine, which greatly reduces the cost; reduces the energy consumption for generating high pressure, produces energy-saving effects, and has a high performance coefficient.

2. Simple structure: The high-pressure water pump is removed, system-related components are reduced, energy consumption is reduced, the structure is simpler, maintenance is more convenient, and the life of the system is also improved. .

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

Description of drawings

Fig. 1 is a structural schematic diagram of a reverse osmosis brine desalination system based on an electrically non-uniform concentration field according to the present invention.

In the figure, 1 desalination chamber, 11 brine inlet of desalination chamber, 12 fresh water outlet of desalination chamber, 101 electrode pair, 102 reverse osmosis membrane, 13 concentrated water outlet of desalination chamber,

2 fresh water pools, 21 fresh water pool fresh water inlets,

3 thick water pools, 31 thick water pool thick water inlets.

Detailed ways

As shown in Figure 1, the reverse osmosis seawater desalination system based on the electro-inhomogeneous concentration field of the present invention includes a desalination chamber 1, a fresh water pool 2, and a concentrated water pool 3. The brine inlet 11 of the desalination chamber is connected with the external brine water source, and The fresh water outlet 12 is connected to the fresh water inlet 21 of the fresh water tank 2, and the concentrated water outlet 13 of the desalination chamber is connected to the concentrated water inlet 31 of the concentrated water tank 3.

It also includes a functional unit for inhomogeneous concentration field desalination;

The non-uniform concentration field desalination functional unit includes at least one electrode pair 101 and a reverse osmosis membrane 102;

The electrode pair 101 is placed in the desalination chamber 1, and the reverse osmosis membrane 102 is placed at the fresh water outlet 12 of the desalination chamber.

Preferably,

The reverse osmosis membrane 102 completely covers the water passage between the fresh water outlet 12 of the desalination chamber and the fresh water inlet 21 of the fresh water tank 2 .

The reverse osmosis membrane 102 covers all or part of the fresh water outlet 12 of the desalination chamber, and the uncovered part of the salt water cannot pass through. Thereby ensuring the purity of fresh water.

Preferably,

The direction of the electric field of the electrode pair 101 is perpendicular to the line connecting the brine inlet 11 and the fresh water outlet 12 of the desalination chamber.

The electrode pair 101 may be one or more than one pair. The electrode is connected to a renewable energy generating device.

The working principle of the reverse osmosis brine desalination system based on the electro-inhomogeneous concentration field of the present invention is as follows:

After the electrode is energized, an electric field is generated to attract the anion and cation of the solute molecules to the surface of the electrode and near the electrode, resulting in an area of uneven concentration in the desalination chamber. The area with a concentration as low as 0 in the brine can be regarded as a fresh water area, and there is no penetration in this area. Under pressure, water molecules can freely pass through the reverse osmosis membrane, which has the effect of separating salt solute molecules from water molecules. In this process, there is no need for a high-pressure water pump to pressurize the brine, which greatly reduces the cost; reduces the energy consumption for generating high pressure, and produces energy-saving effects. The detailed working process is as follows:

The brine inlet of the desalination chamber is connected with the external brine water source. According to the water level, the brine can be injected into the desalination chamber under the action of gravity or by ordinary low-pressure water pump. One or more pairs of electrodes are placed in the desalination chamber, and the electrodes are connected to external power sources, such as solar cells. After the electrodes are energized, an electric field is generated in the desalination chamber. The cations and anions of the solute electrolyte in the brine move under the action of the electric field, the cations migrate to the cathode, and the anions migrate to the anode; the migration makes the concentration of the brine in the desalination chamber no longer uniform, the concentration of the electrode surface and nearby is higher, and the distance from the electrode is farther away The concentration is low, and even the area where the concentration of brine is 0; the osmotic pressure of the area where the concentration is as low as 0 is 0, and the water molecules here can freely pass through the reverse osmosis membrane without the pressure of the high-pressure pump; fresh water in the desalination room The outlet 12 is connected to the fresh water inlet 21 of the fresh water pool 2, and the pure water enters the fresh water pool through the reverse osmosis membrane, realizing the desalination of salt water and the acquisition of pure water; 13 links to each other with the thick water inlet 31 of thick water pool 3, and strong brine enters in the thick water pool and can be used as other recyclable materials. This process continues.

Claims (1)

1. A reverse osmosis seawater desalination system based on an electro-induced inhomogeneous concentration field, including a desalination chamber (1), a fresh water pool (2), a concentrated water pool (3), and the brine inlet (11) of the desalination chamber is connected to an external brine source, The fresh water outlet (12) of the desalination chamber is connected to the fresh water inlet (21) of the fresh water tank, and the concentrated water outlet (13) of the desalination chamber is connected to the concentrated water inlet (31) of the concentrated water tank; the features are: It also includes a functional unit for inhomogeneous concentration field desalination; The non-uniform concentration field desalination functional unit includes at least one electrode pair (101) and a reverse osmosis membrane (102); The electrode pair (101) is placed in the desalination chamber (1), and the reverse osmosis membrane (102) is placed at the fresh water outlet (12) of the desalination chamber; The reverse osmosis membrane (102) fully covers the water passage between the fresh water outlet (12) of the desalination chamber and the fresh water inlet (21) of the fresh water pool; The direction of the electric field of the electrode pair (101) is perpendicular to the line connecting the brine inlet (11) of the desalination chamber and the fresh water outlet (12) of the desalination chamber.

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