The invention content is as follows:
the utility model aims at overcoming the not enough of prior art, provide a based on solar photothermal sea water desalination integration system.
The second objective of the utility model is to provide a method for desalinating seawater by using the solar photo-thermal seawater desalination integrated system.
1. An integrated system for seawater desalination by solar energy photo-thermal, comprising: the system comprises a solar heat collection system, a seawater flash evaporation system, a waste heat recovery system and a seawater desalination control system;
the solar heat collection system comprises a solar water inlet 1, a pressurizing circulating pump 16, a solar heat collector 2 and a solar water outlet 3;
the solar radiation illumination meter is arranged on the surface of the solar heat collector, and the first temperature sensor is arranged on the solar heat collector;
the solar heat collector is sequentially connected with a throttling electromagnetic valve and a solar water outlet pipeline through pipelines, and a solar water inlet and a solar water outlet are connected with the seawater desalination and waste heat recovery integrated system;
the seawater flash evaporation system and the waste heat recovery system are of an integrated molding structure; the integrated forming structure is divided into three layers, wherein the bottom layer is a distillation layer 5, the middle layer is a fresh water layer 6, and the upper layer is a seawater layer 7; the three-layer structure is separated by a partition plate, the partition plate is provided with an opening, the middle heat conduction plate 9 penetrates up and down, and the opening is sealed;
the integrated structure comprises a steam connecting pipe, a distillation layer, a fresh water layer, a seawater inlet pipe, an intermediate heat conducting plate, a seawater replenishing port, a distilled water outlet, a sewage discharge port, a seawater filter, a vacuum pump and the like;
the lowest part of the integrated structure is a distillation layer; the distillation layer is communicated with the seawater layer through a seawater inlet pipe 8, and a water supplementing electromagnetic valve 15 is arranged on the seawater inlet pipe; the water replenishing electromagnetic valve is positioned on a connecting pipeline between the seawater layer and the distillation layer; the solar water outlet is connected with a seawater sprayer; the seawater sprayer is positioned inside the distillation layer; the side wall of the distillation layer is provided with a sewage outlet 12,
the middle layer of the integrated structure is a fresh water layer, and the side wall of one side of the fresh water layer is communicated with the distillation layer through a steam connecting pipe 4; a distilled water outlet 11 and a vacuum pump connecting port are arranged on the other side wall of the fresh water layer; the vacuum pump connecting port is positioned at the upper part of the distilled water outlet and is used for connecting a vacuum pump 19;
the uppermost part of the integrated structure is a seawater layer, and the side walls of two ends of the seawater layer are respectively provided with a seawater replenishing port 10 and a seawater inlet pipe 8.
Furthermore, the middle heat conducting plate 9 penetrates through the three layers up and down, and divides the flow channel to be arranged in a snake shape.
Further, a second temperature sensor is provided in the distillation layer, a third temperature sensor is provided in the fresh water layer, and a fourth temperature sensor is provided in the sea water layer.
An integrated system for seawater desalination by solar energy photo-thermal, comprising: the system comprises a solar heat collection system, a seawater flash evaporation system, a waste heat recovery system and a seawater desalination control system. The seawater flash evaporation system and the waste heat recovery system are integrated and comprise a steam connecting pipe, a distillation layer, a fresh water layer, a seawater inlet pipe, an intermediate heat conducting plate, a seawater water replenishing port, a distilled water outlet, a sewage draining port, a seawater filter, a vacuum pump and the like.
1. The solar heat collection system comprises a solar water inlet, a pressurizing circulating pump, a solar heat collector and a solar water outlet. In the patent, a plurality of solar heat collectors are arranged to be used in series or in parallel according to the required fresh water production capacity. The solar heat collector can be a flat plate type, vacuum tube type or trough type light-gathering solar heat collector, and the type is not limited. The solar heat collector can be an energy storage type or a non-energy storage type, and the energy storage type is not limited. The solar heat collection temperature can reach 100-150 ℃. The solar radiation illumination meter is arranged on the surface of the solar heat collector, and the first temperature sensor is arranged in the solar heat collector and used for measuring the heat collection temperature of seawater.
The solar heat collector is sequentially connected with a throttling electromagnetic valve and a solar water outlet pipeline through pipelines, and the throttling electromagnetic valve is used for controlling the pressure of the throttled seawater and adjusting the gas phase fraction. The pressurizing circulating pump is respectively connected with the solar inlet and the solar outlet and the solar heat collector through pipelines, and is used for circulating seawater and increasing the pressure of the seawater.
The solar water inlet and the solar water outlet are connected with the seawater desalination and waste heat recovery integrated system. The solar water inlet and the solar water outlet are made of stainless steel or brass and are coated with an anticorrosive coating system; the material is polyurethane, epoxy resin or fluororesin, and the thickness is 50-200 microns. The solar water inlet pipeline and the solar outlet pipeline are inserted into the integrated structure of the seawater flash evaporation and waste heat recovery system and enter the distillation layer. The length of a solar water outlet pipeline inside the distillation layer is greater than that of a solar water inlet and outlet pipeline, and a solar water outlet is approximately positioned right below the steam connecting pipe.
2. The seawater flash evaporation system and the waste heat recovery system are of an integrated forming structure. The integrated structure is made of stainless steel, aluminum alloy or copper alloy. The integrated forming structure is divided into three layers, wherein the bottom layer is a distillation layer, the middle layer is a fresh water layer, and the upper layer is a seawater layer. The three-layer structure is separated by a partition plate, the partition plate is provided with an opening, the middle heat conduction plate penetrates up and down, and the opening is sealed. The partition plate is made of stainless steel, aluminum alloy or copper alloy. The middle heat conducting plate is a copper plate, an aluminum plate, a graphene plate or a flat heat pipe, and the thickness of the plate is 2-5 mm. The integrated structure comprises a steam connecting pipe, a distillation layer, a fresh water layer, a seawater inlet pipe, an intermediate heat conducting plate, a seawater replenishing port, a distilled water outlet, a drain outlet, a seawater filter, a vacuum pump and the like. The integrated structure is internally coated with an anticorrosive coating system which is made of polyurethane, epoxy resin or fluororesin and has the thickness of 50-200 microns.
The lowest part of the integrated structure is a distillation layer, and a liquid level meter and a foam suppressor are arranged in the distillation layer. The defoaming device is composed of a fine-mesh wire mesh, such as a wire mesh with 200-500 meshes, and is made of corrosion-resistant materials, such as stainless steel wires, brass wires or carbon fiber wires. The solar water inlet and the solar water outlet are inserted into the distillation layer through pipelines, the solar water inlet is close to the bottom of the distillation layer, and the solar water outlet is close to the upper part of the distillation layer. The distillation layer and the seawater layer are connected through a seawater inlet pipe, and a water replenishing electromagnetic valve is arranged on the seawater inlet pipeline. The water replenishing electromagnetic valve is positioned on a connecting pipeline between the seawater layer and the distillation layer. The solar water outlet is connected with a seawater sprayer. The seawater sprayer is positioned inside the distillation layer. And a drain outlet is arranged on the side wall of the distillation layer close to the bottom of the distillation layer and used for discharging strong brine. The drain outlet is connected with the high salt water sewage pump in sequence through a pipeline.
The middle layer of the integrated structure is a fresh water layer, and one side wall of the fresh water layer is communicated with the distillation layer through a steam connecting pipe. And a distilled water outlet and a vacuum tube pump connecting port are arranged on the other side wall of the fresh water layer. The vacuum pump connecting port is positioned at the upper part of the distilled water outlet. The vacuum pump is connected with a vacuum pump connecting port through a pipeline, and the fresh water layer is pumped into a decompression state according to pressure requirements. The distillation layer is communicated with the fresh water layer through a steam connecting pipe and is in a pressure reduction state, so that the flash evaporation temperature of seawater can be reduced, and the yield of fresh water can be increased. The vacuum pump is universal equipment and can be purchased in the market.
The uppermost part of the integrated structure is a seawater layer, and the side walls of two ends of the seawater layer are respectively provided with a seawater replenishing port and a seawater inlet pipe. The seawater filter is connected with the inlet of the seawater replenishing port through a pipeline and is used for removing impurities such as particle silt, colloid, microorganisms and the like in the surface seawater.
3. The seawater flash evaporation system and the waste heat recovery system are integrally formed and are designed into a three-layer structure, namely a distillation layer, a fresh water layer and a seawater layer. The middle heat conducting plate penetrates through the three layers up and down, and the divided flow channels are arranged in a snake shape. The fluid flows from left to right in the distillation layer and the fresh water layer, and the temperature is gradually reduced; the liquid flows from right to left in the seawater layer, and the temperature is gradually increased. Cold and hot fluid forms countercurrent in the snakelike flow channel of each layer, and the steam condensation and waste heat recovery effects are enhanced. The integrated structure comprises a steam connecting pipe and a seawater inlet pipe, wherein the pipe is made of aluminum alloy, copper alloy or stainless steel. The steam connecting pipe guides the steam generated by the distillation layer into the fresh water layer, the steam is subjected to heat exchange with the middle heat conducting plate and condensed into distilled water, the middle heat conducting plate transfers the heat upwards to exchange heat with the fluid of the sea water layer, and the sea water inlet pipe guides the preheated sea water into the distillation layer. The distillation layer is provided with a second temperature sensor, the freshwater layer is provided with a third temperature sensor, and the seawater layer is provided with a fourth temperature sensor.
4. The seawater desalination control system comprises a Programmable Logic Controller (PLC), a temperature and pressure sensor, a circulation controller, a flow sensor and a vacuum degree sensor. And the programmable logic controller PLC is connected with and collects data of all the liquid level meters, the temperature sensor, the pressure sensor and the solar radiation illumination meter. And running the compiled program according to the parameters such as temperature, pressure, flow and vacuum degree fed back by the sensor, thereby executing control strategies such as solar heat collection circulation, flash evaporation, water supplement, pollution discharge, vacuum degree adjustment and the like.
The utility model discloses a components and parts can be purchased from the market as required, are general, nevertheless need possess certain sea water corrosion resisting property. The programmable logic controller PLC can be a universal controller, and brands such as Siemens, Shinaide or Nanda Aotou and the like can meet the functional requirements.
The technical implementation scheme of the utility model is as follows:
seawater is conveyed from a solar water inlet 1 to a solar heat collector 2 through a pressurizing circulating pump 16, heated and sprayed from a solar water outlet 3 into a distillation layer 5 to be flashed to form vapor; the water vapor upwards enters a fresh water layer 6 through a steam connecting pipe 4, the seawater which is not evaporated returns to the bottom of a distillation layer 5, and then enters a solar water inlet 1 again for cyclic heating distillation; after the water vapor contacts the middle heat conducting plate 9 in the fresh water layer 6, the water vapor is condensed to form fresh water and release heat; the fresh water flows from left to right along the serpentine flow channel, the heat is continuously transferred upwards through the middle heat conducting plate 9, and the temperature of the fresh water is continuously reduced; when the fresh water reaches the rightmost end of the fresh water layer 6, the temperature is reduced to about 15-40 ℃, and the fresh water flows out from the distilled water outlet 11; the vacuum pump connecting port is positioned at the upper part of the distilled water outlet, the vacuum pump 19 pumps the fresh water layer 6 into a decompression state through the vacuum pump connecting port, and the distillation layer 5 is communicated with the fresh water layer 6 through the steam connecting pipe 4 and is in the decompression state; the seawater desalination control system can control the vacuum pump 19 to regulate and control the decompression state of the distillation process.
The distillation layer 5, the fresh water layer 6 and the seawater layer 7 are divided into three layers by partition plates, and a middle heat conduction plate 9 penetrates through the distillation layer from top to bottom; the middle heat conducting plate 9 absorbs the seawater in the distillation layer 5 and the heat contained in the steam and the distilled water in the fresh water layer 6, quickly transfers the heat upwards, and exchanges heat and stores the heat to the fresh seawater in the seawater layer 7; fresh seawater enters a seawater layer 7 from a seawater replenishing port 10, is heated by an intermediate heat conduction plate 9 and then enters a distillation layer 5 through a seawater inlet pipe 8;
distilled water in the fresh water layer 6 flows out from a distilled water outlet 11 after heat is recovered through the middle heat conducting plate 9; the high-salt concentration seawater in the distillation layer 5 flows out from the sewage outlet 12 after the heat is recovered by the middle heat-conducting plate 9. The distillation layer 5, the fresh water layer 6 and the seawater layer 7 are divided into serpentine flow channels by the middle heat conduction plate 9, and fluid in the distillation layer 5 and the fresh water layer 6 flows from left to right, the temperature is gradually reduced, and the fluid is discharged from a water outlet at the right side; the fluid in the sea water layer 7 is fed from the water inlet at the right side, flows from the right side to the left side, and the temperature is gradually increased. In order to improve the heat recovery effect, the length of the integrated box body structure can be prolonged, and the number of the middle heat conducting plates is increased, so that the length of the snake-shaped flow channel for countercurrent heat exchange is increased.
The patent also provides a method for desalinating seawater by utilizing the solar photo-thermal seawater desalination integrated system, which comprises the following specific steps:
seawater is conveyed from a solar water inlet 1 to a solar heat collector 2 through a pressurizing circulating pump 16 to be heated; when the temperature of seawater in the solar heat collector 2 reaches 60-120 ℃ and the pressure reaches 0.2-0.5 MPa (A), opening the throttling electromagnetic valve 14 to introduce the seawater into the distillation layer 5 for flash evaporation; the pressure of the undistilled seawater and the water vapor is reduced to 0.01-0.1MPa (A), the temperature is reduced to 50-100 ℃, the water vapor upwards enters a fresh water layer 6 through a steam connecting pipe 4, the undistilled seawater returns to the bottom of a distillation layer 5, and enters a solar water inlet 1 again for cyclic heating distillation; after the water vapor contacts the middle heat conducting plate 9 in the fresh water layer 6, the water vapor is condensed to form fresh water and release heat; the temperature of the fresh water at the leftmost end of the fresh water layer 6 is 50-100 ℃, the fresh water flows rightwards in the snake-shaped flow channel of the fresh water layer 6, continuously exchanges heat with the middle heat conducting plate 9, the temperature is reduced to 15-40 ℃ when the fresh water reaches the rightmost end, and the fresh water flows out from the distilled water outlet 11; fresh seawater passes through a seawater filter 18 and then enters a seawater layer from a seawater replenishing port 10; the temperature of fresh seawater at the rightmost end of the seawater layer 7 is 5-25 ℃, the fresh seawater flows leftwards in the snake-shaped flow channel of the seawater layer 7 and continuously exchanges heat with the middle heat conducting plate 9, the temperature is increased to 50-100 ℃ when the fresh seawater reaches the leftmost end, and the fresh seawater enters the distillation layer 5 from the seawater inlet pipe 8 when the water replenishing electromagnetic valve 15 is opened; the temperature of the seawater at the bottom of the distillation layer 5 is 50-100 ℃, one part of the seawater enters the solar heat collector 2 through the solar water inlet 1 for heating, the other part of the seawater flows rightwards in the snake-shaped flow channel of the distillation layer 5, continuously exchanges heat with the middle heat-conducting plate 9, the temperature of the seawater at the rightmost end is reduced to 15-40 ℃ (the seawater exchanges heat through the middle heat-conducting plate), and the seawater flows out of the sewage outlet 12; a liquid level sensor is arranged in the distillation layer 5, along with the continuous evaporation of the seawater in the distillation layer 5 and the discharge of the seawater from a sewage discharge outlet 12, when the liquid level is reduced to below 25 percent, a water replenishing electromagnetic valve 15 is opened to continuously replenish fully preheated fresh seawater from a seawater inlet pipe 8, the fluctuation of the liquid level of the seawater in the distillation layer 5 is maintained to be not more than +/-10 percent, the temperature control range is 45-120 ℃, the pressure control range is 0.01-0.1MPa (A), and the concentration of the seawater floats to be within +/-5 percent; according to the temperature of the seawater in the solar heat collector 2, the pressure of the fresh water layer 6, the steam connecting pipe 4 and the distillation layer 5 is adjusted through the vacuum pump 19, and the lower the temperature of the seawater is, the lower the pressure is, so that the pressure in the distillation layer 5 is ensured to be smaller than the saturated vapor pressure of the seawater at the temperature; and when the temperature of the seawater in the solar heat collector 2 is lower than 60 ℃, stopping the booster circulating pump 16 and the vacuum pump 19, and ending the seawater desalination process.
The beneficial effect of this patent:
1. the whole system is designed in an integrated manner, is simple and efficient, fully recovers the residual heat of water vapor, distilled water and high-salinity seawater, reduces the heating pressure of the solar heat collector, can continuously desalt seawater by only using a small amount of solar heat, and has great popularization significance.
2. The integrated structure of seawater desalination and waste heat recovery is a three-layer structure design, and an internal distillation layer, a fresh water layer and a seawater layer are divided by a middle heat conducting plate and are arranged in a 'snake-shaped' flow passage. The cold and hot fluid flows through the middle heat conducting plate for countercurrent heat exchange. The serpentine flow channel countercurrent design of each layer ensures sufficient heat exchange temperature difference and stable waste heat recovery effect. The distillation layer plays a role of a reboiler of the distillation tower, enhances the gasification of the heated seawater, enhances the recovery of waste heat and increases the recovery rate of fresh water. The high temperature side is formed at the distillation side, the low temperature side is formed at the other inlet and outlet side, and the solar heat is only used for heating the liquid at the high temperature side for gasification. Along with the continuous operation of the total heat recovery process, the steam is condensed to transfer heat to the high-temperature side and the low-temperature side, and the supplemented fresh seawater reversely brings the heat of the low-temperature side back to the high-temperature side continuously.
3. The system adopts the integrated design of seawater desalination and waste heat recovery, thereby not only recovering the latent heat of condensation of water vapor, but also utilizing the sensible heat of concentrated seawater and distilled water, increasing the heat exchange area and the heat exchange time, and improving the energy recovery efficiency. Meanwhile, the condensation speed of the water vapor is increased, and the yield of the fresh water is improved. The water yield of the unit daylighting area of the traditional passive solar distiller is too low and is only 5-10 kg/m2D, the yield of fresh water produced by each square meter of the heat collector of the solar seawater desalination system designed by the system can reach more than 35L per square meter.
Detailed Description
The technical implementation scheme of the utility model is as follows:
seawater is conveyed from a solar water inlet 1 to a solar heat collector 2 through a pressurizing circulating pump 16, heated and sprayed from a solar water outlet 3 into a distillation layer 5 to be flashed to form vapor; the water vapor upwards enters a fresh water layer 6 through a steam connecting pipe 4, the seawater which is not evaporated returns to the bottom of a distillation layer 5, and then enters a solar water inlet 1 again for cyclic heating distillation; after the water vapor contacts the middle heat conducting plate 9 in the fresh water layer 6, the water vapor is condensed to form fresh water and release heat; the fresh water flows from left to right along the serpentine flow channel, the heat is continuously transferred upwards through the middle heat conducting plate 9, and the temperature of the fresh water is continuously reduced; when the fresh water reaches the rightmost end of the fresh water layer 6, the temperature is reduced to about 15-40 ℃, and the fresh water flows out from the distilled water outlet 11; the vacuum pump connecting port is positioned at the upper part of the distilled water outlet, the vacuum pump 19 pumps the fresh water layer 6 into a decompression state through the vacuum pump connecting port, and the distillation layer 5 is communicated with the fresh water layer 6 through the steam connecting pipe 4 and is in the decompression state; the seawater desalination control system can control the vacuum pump 19 to regulate and control the decompression state of the distillation process.
The distillation layer 5, the fresh water layer 6 and the seawater layer 7 are divided into three layers by partition plates, and a middle heat conduction plate 9 penetrates through the distillation layer from top to bottom; the middle heat conducting plate 9 absorbs the seawater in the distillation layer 5 and the heat contained in the steam and the distilled water in the fresh water layer 6 and rapidly transfers the heat upwards to exchange heat to the fresh seawater in the seawater layer 7; fresh seawater enters a seawater layer 7 from a seawater replenishing port 10, is heated by an intermediate heat conduction plate 9 and then enters a distillation layer 5 through a seawater inlet pipe 8;
distilled water in the fresh water layer 6 flows out from a distilled water outlet 11 after heat is recovered through the middle heat conducting plate 9; the high-salt concentration seawater in the distillation layer 5 flows out from the sewage outlet 12 after the heat is recovered by the middle heat-conducting plate 9. The distillation layer 5, the fresh water layer 6 and the seawater layer 7 are divided into serpentine flow channels by the middle heat conduction plate 9, and fluid in the distillation layer 5 and the fresh water layer 6 flows from left to right, the temperature is gradually reduced, and the fluid is discharged from a water outlet at the right side; the fluid in the sea water layer 7 is fed from the water inlet at the right side, flows from the right side to the left side, and the temperature is gradually increased. In order to improve the heat recovery effect, the length of the water tank can be prolonged, and the number of the middle heat conducting plates can be increased, so that the length of the countercurrent heat exchange of the snake-shaped flow channel is increased.
The patent also provides a method for desalinating seawater by utilizing the solar photo-thermal seawater desalination integrated system, which comprises the following specific steps:
seawater is conveyed from a solar water inlet 1 to a solar heat collector 2 through a pressurizing circulating pump 16 to be heated; when the temperature of seawater in the solar heat collector 2 reaches 60-120 ℃ and the pressure reaches 0.2-0.5 Mpa (A), opening the throttling electromagnetic valve 14 to introduce the seawater into the distillation layer 5 for flash evaporation; the pressure of the undistilled seawater and the water vapor is reduced to 0.01-0.1Mpa (A), the temperature is reduced to 50-100 ℃, the water vapor upwards enters a fresh water layer 6 through a steam connecting pipe 4, the undistilled seawater returns to the bottom of a distillation layer 5, and enters a solar water inlet 1 again for cyclic heating distillation; after the water vapor contacts the middle heat conducting plate 9 in the fresh water layer 6, the water vapor is condensed to form fresh water and release heat; the temperature of the fresh water at the leftmost end of the fresh water layer 6 is 50-100 ℃, the fresh water flows rightwards in the snake-shaped flow channel of the fresh water layer 6, continuously exchanges heat with the middle heat conducting plate 9, the temperature is reduced to 15-40 ℃ when the fresh water reaches the rightmost end, and the fresh water flows out from the distilled water outlet 11; fresh seawater passes through a seawater filter 18 and then enters a seawater layer from a seawater replenishing port 10; the temperature of fresh seawater at the rightmost end of the seawater layer 7 is 5-25 ℃, the fresh seawater flows leftwards in the snake-shaped flow channel of the seawater layer 7, continuously exchanges heat with the middle heat conducting plate 9, the temperature rises to 50-100 ℃ when reaching the leftmost end, and the fresh seawater enters the distillation layer 5 from the seawater inlet pipe 8 when the water replenishing electromagnetic valve 15 is opened; the temperature of seawater at the bottom of the distillation layer 5 is 50-100 ℃, one part of seawater enters the solar heat collector 2 through the solar water inlet 1 for heating, the other part of seawater flows rightwards in the snake-shaped flow channel of the distillation layer 5, continuously exchanges heat with the middle heat-conducting plate 9, the temperature of the seawater at the rightmost end is reduced to 15-40 ℃ (the seawater is exchanged heat through the middle heat-conducting plate), and the seawater flows out of the sewage outlet 12; a liquid level sensor is arranged in the distillation layer 5, along with the continuous evaporation of the seawater in the distillation layer 5 and the discharge of the seawater from a sewage discharge outlet 12, when the liquid level is reduced to below 25%, a water replenishing electromagnetic valve 15 is opened to continuously replenish fully preheated fresh seawater from a seawater inlet pipe 8, the fluctuation of the liquid level of the seawater in the distillation layer 5 is maintained to be not more than +/-10%, the temperature control range is 45-120 ℃, the pressure is controlled to be 0.01-0.1Mpa (A), and the concentration of the seawater in the distillation layer floats to be within +/-5%; according to the temperature of the seawater in the solar heat collector 2, the vacuum degree of the fresh water layer 6 and the vacuum degree of the distillation layer 5 are adjusted through the vacuum pump 19, the lower the temperature of the seawater is, the higher the vacuum degree is, and the pressure in the distillation layer 5 is ensured to be smaller than the saturated vapor pressure of the seawater at the temperature; and when the temperature of the seawater in the solar heat collector 2 is lower than 60 ℃, stopping the booster circulating pump 16 and the vacuum pump 19, and ending the seawater desalination process.