CN201737726U - Solar seawater-desalinating device adopting passive flash evaporation technique - Google Patents

Abstract

The utility model belongs to the technical field of desalination of seawater by using solar energy, in particular to a passive flash solar desalination device. The device removes the non-condensable gas in the flash chamber and condenser before working, and continuously removes the non-condensable gas generated in the seawater desalination project by intermittently opening and closing the control valve during the working process; the flash chamber and the condenser are respectively connected to the seawater tank and the freshwater tank on the ground through pipes. The pressure difference of the seawater in the pipe makes the flash chamber in a low-pressure state, thereby reducing the boiling point of the seawater in the flash chamber and flashing; after the seawater is heated in the heat exchanger , relying on the siphon effect to enter the flash chamber, passive flash evaporation, and the low pressure in the flash chamber does not need to be maintained by a vacuum pump. The utility model makes full use of renewable and environment-friendly solar energy, and has high efficiency, low cost and convenient operation.

Description

Passive flash solar desalination device

technical field

The utility model belongs to the technical field of desalination of seawater by using solar energy, in particular to a device which uses solar energy as a heat source and utilizes gravity pressure difference to realize flash desalination of seawater.

Background technique

With the development of science and technology, great progress has been made in solar energy, energy-saving technology and seawater desalination. Its development trend is to use renewable and environmentally friendly energy as much as possible, and provide people with high-quality resources at low cost. Because solar energy is inexhaustible, inexhaustible, rich in resources, and non-polluting to the environment, it has broad prospects for utilization and development. In recent years, with the development of solar technology, people have begun to use solar energy for desalination of seawater. At present, the relatively mature seawater desalination technologies are mainly multi-effect distillation, multi-effect flash evaporation and membrane osmosis. However, the above-mentioned technologies are mainly suitable for large-scale seawater desalination, and the system is complex, with high maintenance costs and high investment costs.

Compared with traditional seawater desalination, using gravity pressure difference to achieve flash desalination of seawater has the advantages of simple technology, convenient operation, and no need for mechanical devices such as vacuum pumps to maintain the low pressure state in the flash chamber, which determines that this technology and device have the advantages of Good promotional value. At the same time, due to non-condensable gases dissolved in seawater, when the seawater desalination system operates for a period of time, non-condensable gases will accumulate in the flash chamber and condenser. If these gases are not eliminated, the pressure in the flash chamber will gradually decrease. until the seawater desalination stops, it is necessary to add a device for regularly removing non-condensable gases, so that the seawater desalination system can continue to operate, which is also a key technology of this patent.

Contents of the invention

The purpose of the utility model is to solve the problems of high seawater desalination cost and heavy pollution in the prior art, and provide a solar seawater desalination device with high efficiency, low cost and environmental protection.

The technical scheme of the utility model is: a seawater pool, the seawater pool is connected with the water storage tank through a water pump and a seawater pipeline; the input end of the condenser is connected with the water storage tank, and the output end of the condenser is connected with the input end of the heat exchanger , the output end of the heat exchanger is connected to the flash chamber, there is a pipeline between the condenser and the flash chamber, and the heat exchanger is connected to the solar collector through two pipelines; the condenser and the heat exchanger are respectively set Solenoid; the bottom of the condenser is provided with a fresh water outlet, which is connected to the fresh water tank through a fresh water pipeline; the bottom of the flash chamber is provided with a concentrated seawater outlet, which is connected to the concentrated seawater tank through a concentrated seawater pipeline; the side wall of the condenser is provided with a pipeline, which is connected with the storage A pipeline connected to the pool is merged into a seawater pool and a non-condensable gas discharge pipeline to lead into the seawater pool.

The solar heat collector is a flat plate solar heat collector or a vacuum tube type solar heat collector.

The condenser is a single-stage condenser or a multi-stage condenser; the flash chamber is a single-stage flash chamber or a multi-stage flash chamber.

The solar heat collector, flash chamber, condenser and water storage tank are not less than 8m from the ground and kept airtight.

Discharge valves are respectively arranged on the water storage tank and the condenser.

Control valves are respectively set on the two branches of the seawater and the noncondensable gas discharge pipeline, the freshwater pipeline and the concentrated seawater pipeline.

The beneficial effects of the utility model are: the device utilizes the gravity pressure difference to realize the flash desalination of seawater, does not need a vacuum pump to maintain the low pressure state in the flash chamber, and the replenishment of seawater in the flash chamber and the circulation of liquid in the solar collector are both It is realized by natural convection, which reduces the investment cost and energy consumption of the seawater desalination device, and has good promotion value; during the operation of the device, non-condensable gases can be regularly removed, so that the seawater desalination system can continue The operation can improve the use value and work efficiency; the structure is simple, the operation is convenient, the thermal efficiency is improved and the investment cost is reduced, and it also provides a good means and method for further research on the use of solar energy for seawater desalination.

Description of drawings

Figure 1 is a schematic diagram of a passive flash solar desalination device of the present invention

Reference signs:

1-sea water pool; 2-water pump; 3-reservoir; 4-condenser; 5-flash chamber; 6-heat exchanger;

7-solar heat collector; 8-concentrated sea water tank; 9-fresh water tank; 10-sea water pipeline;

11-seawater and non-condensable gas discharge pipeline; 12-fresh water pipeline; 13-concentrated seawater pipeline;

14-reservoir discharge valve; 15-condenser discharge valve; 16-first control valve;

17-the second control valve; 18-the third control valve; 19-the fourth control valve;

20—fifth control valve; 21—solenoid.

Detailed ways

The utility model provides a passive flash solar desalination device. The utility model will be further described below in conjunction with the accompanying drawings and specific implementation methods.

Fig. 1 is the structural representation of the utility model. The device is provided with a seawater pool 1, and the seawater pool 1 is connected with the water storage tank 3 through the water pump 2 and the seawater pipeline 10; the input end of the condenser 4 is connected with the water storage tank 3, and the output end of the condenser 4 is connected with the heat exchanger 6 The input end of the heat exchanger 6 is connected to the flash chamber 5, and there is a pipeline between the condenser 4 and the flash chamber 5, and the heat exchanger 6 is connected to the solar collector 7 through two pipelines. connection; the condenser 4 and the heat exchanger 6 are respectively provided with a solenoid 21; the bottom of the condenser 4 is provided with a fresh water outlet, which is passed into the fresh water tank 9 through a fresh water pipeline 12; the bottom of the flash chamber 5 is provided with a concentrated seawater outlet, which is passed through The pipeline 13 leads into the concentrated seawater tank 8; the side wall of the condenser 4 is provided with a pipeline, and a pipeline connected with the reservoir 3 is merged into seawater and a noncondensable gas discharge pipeline 11, which is passed into the seawater pool 1. Wherein, the solar heat collector 7, the flash chamber 5, the condenser 4 and the water storage tank 3 are 10m away from the ground and kept airtight. The condenser 4 has the functions of preheating seawater and condensing steam, and the spiral tube 21 in the condenser 4 is a part for realizing heat exchange. The solar heat collector 7 collects solar energy and heats the seawater in the heat exchanger 6. The seawater with increased temperature is siphoned into the flash chamber 5 for flash evaporation, and the steam generated by the flash evaporation is condensed in the condenser 4 to form fresh water. The fresh water flows into the fresh water tank 9 through the fresh water pipeline 12 , and the concentrated seawater produced after flash evaporation is discharged into the concentrated seawater tank 8 through the concentrated seawater pipeline 13 .

Before the start-up process of the seawater desalination device, close the first control valve 16-fifth control valve 20, vacuumize the flash chamber 5 and the condenser 4, the condenser discharge valve 15 is the interface for vacuuming and discharging, and the seawater desalination device starts Then be in closed state; Open the 4th control valve 19 and the 5th control valve 20 then, because be in low pressure state in the flash chamber 5 and condenser 4, so thick seawater and fresh water can be respectively in thick seawater pipeline 13 and freshwater pipeline 12 It rises inside and forms a certain height difference with the ground. The air pressure in the flash chamber 5 is equal to the difference between the atmospheric pressure and the pressure formed by the concentrated seawater in the concentrated seawater pipeline 13 . The flash chamber 5 is under low pressure. On the one hand, the seawater with a higher temperature will flash, and on the other hand, the seawater in the siphon reservoir 3 enters the flash chamber 5 through the condenser 4 and the heat exchanger 6, and realizes Preheating and heating, this process and the operation of the water in the solar collector 7 are all realized by the natural circulation of the liquid, no additional power is needed. The water storage tank discharge valve 14 is in communication with the outside atmosphere during work, so as to maintain the water storage tank 3 in the state of atmospheric pressure. The third control valve 18 controls the amount of seawater entering the flash chamber 5 .

In the seawater desalination process, the removal process of non-condensable gas is as follows: firstly open the first control valve 16 to fill the seawater and non-condensable gas discharge pipeline 11 with seawater, then close the first control valve 16 and open the second control valve 17. At this time, the seawater will flow downward, and part of the non-condensable gas will enter the seawater and the non-condensable gas discharge pipe 11, then close the second control valve 17, and open the first control valve 16 to allow seawater to flow from the reservoir 3 , so that it goes round and round without interruption, so as to realize the elimination of the non-condensable gas in the condenser 4 and the flash chamber 5 .

The flash chamber 5 can be single-stage or multi-stage. The condenser 4 can be used alone, and can also be divided into several stages and connected with the flash chamber for common use. In this embodiment, only the case where the condenser 4 and the flash chamber 5 are single-stage

The solar heat collector 7 can be a flat plate heat collector, or a vacuum tube or a trough heat collector. In this embodiment, a flat plate collector is used.

The seawater desalination device can be used alone or mixed with other seawater desalination methods.

The above detailed description is a specific description of the feasible embodiment of the utility model. The seawater desalination of the system is passive, and in its cycle, except for the process from the seawater pool to the storage pool, the rest of the process does not need power, so that the seawater desalination process Operations with high efficiency, low cost and low energy consumption are realized.

Claims (6)

1. A passive flashing solar desalination device is characterized in that: seawater pool (1), seawater pool (1) is connected to water storage tank (3) by water pump (2) and seawater pipeline (10); condenser ( The input end of 4) is connected with the water storage tank (3), the output end of the condenser (4) is connected with the input end of the heat exchanger (6), and the output end of the heat exchanger (6) is connected with the flash chamber ( 5) connection, there is a pipeline to communicate between the condenser (4) and the flash chamber (5), and the heat exchanger (6) is connected with the solar heat collector (7) by two pipelines; the condenser (4) and Solenoids (21) are respectively arranged in the heat exchanger (6); the fresh water outlet is arranged at the bottom of the condenser (4), and is passed into the fresh water tank (9) through the fresh water pipeline (12); The seawater outlet is passed into the concentrated seawater tank (8) through the concentrated seawater pipeline (13); the side wall of the condenser (4) is provided with a pipeline, which is combined with a pipeline connected to the reservoir (3) to form seawater and non-condensable Sexual gas discharge pipe (11) leads into seawater pool (1). 2. A passive flash solar desalination device according to claim 1, characterized in that: the solar heat collector (7) is a flat plate solar heat collector or a vacuum tube solar heat collector. 3. A kind of passive flash solar desalination device according to claim 1, characterized in that: the condenser (4) is a single-stage condenser or a multi-stage condenser; the flash chamber (5) is Single-stage flash chamber or multi-stage flash chamber. 4. A kind of passive flash solar seawater desalination device according to claim 1, characterized in that: said solar heat collector (7), flash chamber (5), condenser (4) and water storage tank ( 3) The distance from the ground shall not be less than 8m, and shall be kept airtight. 5 . A passive flash solar desalination device according to claim 1 , characterized in that discharge valves are respectively set on the water storage tank ( 3 ) and the condenser ( 4 ). 6. A kind of passive flash solar desalination device according to claim 1, characterized in that: the seawater and the two branches of the noncondensable gas discharge pipeline (11), the freshwater pipeline (12) and the concentrated seawater Control valves are respectively arranged on the pipeline (13).