Zero-carbon seawater desalination device based on LNG (Liquefied Natural Gas) cold energy

Abstract

The invention provides a zero-carbon seawater desalination device based on LNG (Liquefied Natural Gas) cold energy. The zero-carbon seawater desalination device comprises an LNG cold energy utilization pipeline, a photo-thermal heat energy utilization loop, a seawater desalination pipeline, a photovoltaic energy storage device and a heat exchange water tank, the seawater desalination pipeline is provided with a drain valve, a reverse osmosis treatment assembly and a pumping assembly, the input ends of the drain valve and the pumping assembly are connected with the heat exchange water tank through pipelines, and the reverse osmosis treatment assembly is connected with the output end of the pumping assembly; the LNG cold energy utilization pipeline and the photo-thermal heat energy utilization loop are both in heat exchange connection with the heat exchange water tank, the LNG cold energy utilization pipeline is used for providing cold energy for the heat exchange water tank, and the photo-thermal heat energy utilization loop is used for providing heat energy for the heat exchange water tank; the photovoltaic energy storage device is used for supplying power to the zero-carbon seawater desalination device based on the LNG cold energy; according to the invention, energy consumption in the seawater desalination process can be reduced, and zero-carbon circulation is realized in the whole chain.

Description

Technical Field

[0001] The present invention belongs to the technical field of seawater desalination, and in particular relates to a zero-carbon seawater desalination device based on LNG cold energy. Background Art

[0002] Freezing is a common method for desalination. Freezing seawater is used to freeze it, and as the liquid seawater turns to solid ice, the salt is separated out. However, the disadvantage of freezing is that it consumes a lot of energy.

[0003] LNG (liquefied natural gas) is a clean energy source and is widely used in various industries. LNG needs to be gasified during its application. If this cold energy is not recovered in time, a large amount of high-grade LNG cold energy will be seriously wasted.

[0004] In the prior art, there is a technology disclosed for desalinating seawater using the cold energy of LNG, which can reduce the energy consumption of freezing seawater.

[0005] For example, the Chinese utility model patent document with authorization publication number CN220351771U discloses a seawater cooling and desalination system based on LNG cold energy, but it uses an ice heater to melt the frozen ice layer, and the ice heater still consumes a lot of energy to heat and melt the ice layer.

[0006] Therefore, it is necessary to design a zero-carbon seawater desalination device based on LNG cold energy that reduces energy consumption in the seawater desalination process and achieves a zero-carbon cycle in the entire chain to solve the current technical problems. Summary of the Invention

[0007] In response to the shortcomings of the existing technology, the present invention provides a zero-carbon seawater desalination device based on LNG cold energy, which reduces energy consumption in the seawater desalination process and achieves a zero-carbon cycle in the entire chain.

[0008] The technical solution of the present invention is: a zero-carbon seawater desalination device based on LNG cold energy, comprising: an LNG cold energy utilization pipeline, a solar thermal energy utilization loop, a seawater desalination pipeline, a photovoltaic energy storage device and a heat exchange tank; the seawater desalination pipeline has a drain valve, a reverse osmosis treatment component and a pumping component, the drain valve and the input end of the pumping component are connected to the heat exchange tank through a pipeline, and the reverse osmosis treatment component is connected to the output end of the pumping component; the LNG cold energy utilization pipeline and the solar thermal energy utilization loop are respectively connected to the heat exchange tank, the LNG cold energy utilization pipeline is used to provide cold energy to the heat exchange tank, and the solar thermal energy utilization loop is used to provide heat energy to the heat exchange tank; the photovoltaic energy storage device is used to power the zero-carbon seawater desalination device based on LNG cold energy.

[0009] Furthermore, the interior of the heat exchange water tank has a first coil and a second coil; the LNG cold energy utilization pipeline is connected to the first coil inside the heat exchange water tank; and the solar thermal energy utilization circuit is connected to the second coil inside the heat exchange water tank.

[0010] Furthermore, the LNG cold energy utilization pipeline has an LNG storage tank, which is connected to the first coil inside the heat exchange tank through a pipeline. The liquid natural gas inside the LNG storage tank is gasified and absorbs heat inside the first coil and then transported to the industrial building.

[0011] Furthermore, the photovoltaic energy storage device has a photovoltaic component, which is a photovoltaic thermal integrated panel; the thermal energy utilization circuit has a circulation pump, and the circulation pump is connected in series with the second coil and the thermal module of the photovoltaic thermal integrated panel through a pipeline to form a circulation circuit, and the thermal energy utilization circuit is filled with a heat exchange medium.

[0012] Furthermore, the photovoltaic module of the photovoltaic and thermal integrated panel is connected to an energy storage box, and the energy storage box is used to power the zero-carbon seawater desalination device based on LNG cold energy.

[0013] Furthermore, the reverse osmosis treatment component comprises a first reverse osmosis module and a second reverse osmosis module which are sequentially connected in series through pipelines.

[0014] Furthermore, the pumping assembly has a first-level high-pressure pump and a second-level high-pressure pump; the first-level high-pressure pump is connected between the heat exchange water tank and the first reverse osmosis module; the second-level high-pressure pump is connected between the first reverse osmosis module and the second reverse osmosis module; the energy storage box supplies power to the first-level high-pressure pump and the second-level high-pressure pump.

[0015] Furthermore, the output end of the second reverse osmosis module is connected to the industrial building through a pipeline, so as to transport the desalinated seawater to the industrial building.

[0016] Furthermore, the heat exchange water tank is connected to a water supply valve.

[0017] Furthermore, the water supply valve is connected to a seawater pump through a pipeline, and seawater is pumped into the heat exchange water tank through the seawater pump.

[0018] Beneficial effects of the present invention:

[0019] (1) In the present invention, the cold energy and solar thermal energy in the LNG gasification process are combined with seawater desalination, which solves the problem of high energy consumption in the freezing and ice melting process of seawater desalination. In addition, the photovoltaic energy storage device uses photovoltaic power generation and storage. All electrical equipment in the zero-carbon seawater desalination device based on LNG cold energy is powered by photovoltaic power generation, reducing energy consumption in the seawater desalination process and achieving a zero-carbon cycle in the entire chain.

[0020] (2) Seawater is injected into the heat exchanger tank, and the LNG cold energy utilization pipeline supplies gas to the industrial building. The LNG cold energy utilization pipeline absorbs heat during the gas supply process, so that the seawater in the heat exchanger tank forms low-salt ice crystals and concentrated brine. The concentrated brine is discharged from the drain valve. Then, the heat energy provided by the photothermal heat energy utilization loop is used to melt the low-salt ice crystals into low-salt seawater. The pumping component pumps the low-salt seawater through the reverse osmosis treatment component, and the reverse osmosis treatment component intercepts the residual salt ions, heavy metals and dissolved organic matter in the low-salt seawater to provide qualified desalinated water for the industrial building. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of the zero-carbon seawater desalination device based on LNG cold energy in the present invention. DETAILED DESCRIPTION

[0022] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present invention, its application, or use. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present invention thorough and complete and to fully convey the scope of the present invention to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, the composition of materials, numerical expressions, and numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0023] The terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are simply used to distinguish different parts. Terms such as "include" or "comprising" mean that the elements preceding the term include the elements listed after the term, and do not exclude the possibility of also including other elements. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0024] like Figure 1As shown, the zero-carbon seawater desalination device based on LNG cold energy includes: an LNG cold energy utilization pipeline, a solar thermal energy utilization loop, a seawater desalination pipeline, a photovoltaic energy storage device and a heat exchange tank 2; the seawater desalination pipeline has a drain valve 5, a reverse osmosis treatment component and a pumping component, the drain valve 5 and the input end of the pumping component are connected to the heat exchange tank 2 through a pipeline, and the reverse osmosis treatment component is connected to the output end of the pumping component; the LNG cold energy utilization pipeline and the solar thermal energy utilization loop are respectively connected to the heat exchange tank 2 for heat exchange, the LNG cold energy utilization pipeline is used to provide cold energy to the heat exchange tank 2, and the solar thermal energy utilization loop is used to provide heat energy to the heat exchange tank 2; the photovoltaic energy storage device 8 is used to power the zero-carbon seawater desalination device based on LNG cold energy; in this embodiment, seawater is injected into the heat exchange tank 2, the LNG cold energy utilization pipeline supplies gas to the industrial building 11, and the LNG cold energy is used to supply gas to the industrial building 11. The heat absorbed by the liquefied natural gas vaporization during the gas supply process in the pipeline is used to form low-salt ice crystals and concentrated brine in the seawater in the heat exchange tank 2. The concentrated brine is discharged outward from the drain valve 5, and then the heat energy provided by the solar thermal energy utilization loop is used to melt the low-salt ice crystals into low-salt seawater. The pumping component pumps the low-salt seawater through the reverse osmosis treatment component, and the reverse osmosis treatment component intercepts the residual salt ions, heavy metals and dissolved organic matter in the low-salt seawater to provide qualified desalinated water for the industrial building 11; the cold energy and solar thermal energy in the LNG gasification process are combined with seawater desalination to solve the problem of high energy consumption in the freezing and ice melting processes of seawater desalination, and the photovoltaic energy storage device uses photovoltaic power generation and storage. All electrical equipment in the zero-carbon seawater desalination device based on LNG cold energy is provided by photovoltaic power generation, reducing energy consumption in the seawater desalination process and realizing a zero-carbon cycle for the entire chain.

[0025] In some embodiments, the interior of the heat exchange tank 2 has a first coil and a second coil, which are used to increase the heat exchange area between the seawater and ice crystals and improve the heat exchange efficiency; the LNG cold energy utilization pipeline is connected to the first coil inside the heat exchange tank 2, and the liquid natural gas vaporizes and absorbs heat inside the first coil, and the first coil is used to exchange heat with the seawater; the solar thermal energy utilization loop is connected to the second coil inside the heat exchange tank 2, and the solar thermal energy utilization loop continuously circulates the heat exchange medium to achieve heating of the ice crystals inside the heat exchange tank 2.

[0026] In some embodiments, the LNG cold energy utilization pipeline has an LNG storage tank 1, and liquefied natural gas is stored inside the LNG storage tank 1. The LNG storage tank 1 is connected to the first coil inside the heat exchange tank 2 through a pipeline. The liquefied natural gas inside the LNG storage tank 1 is vaporized and absorbs heat inside the first coil and then transported to the industrial building 11. The cold energy generated by absorbing heat during the liquefaction of the liquefied natural gas causes partial freezing of seawater to produce low-salt ice crystals and concentrated brine.

[0027] In some embodiments, the photovoltaic energy storage device has a photovoltaic module 3, which is a photovoltaic thermal integrated panel; the thermal energy utilization circuit has a circulation pump 4, and the circulation pump 4 is connected in series with the second coil and the thermal module of the photovoltaic thermal integrated panel in sequence to form a circulation circuit, and the thermal energy utilization circuit is filled with a heat exchange medium; the circulation pump 4 drives the heat exchange medium to circulate in the thermal energy utilization circuit, and the heat exchange medium transfers the thermal energy obtained from the photovoltaic thermal integrated panel to the heat exchange water tank 2 to melt the low-salt ice crystals in the heat exchange water tank 2; specifically, the heat exchange medium is Freon

[0028] In some embodiments, the photovoltaic module of the photovoltaic and thermal integrated panel is connected to an energy storage box, and the energy storage box 8 is used to power a zero-carbon seawater desalination device based on LNG cold energy.

[0029] In some embodiments, the reverse osmosis treatment component has a first reverse osmosis module 7 and a second reverse osmosis module 9 which are connected in series through pipelines; after the first reverse osmosis module 7 desalinates the low-salinity seawater by 90% to 95%, the second reverse osmosis module 9 further removes the remaining ions, reducing the salinity of the produced water to below 200 ppm, achieving a desalination rate of >98%, meeting the standards for high-purity industrial water or direct drinking; and the two-stage reverse osmosis treatment can efficiently remove small molecules such as boron and silicates remaining in the low-salinity seawater, and the retention rate of heavy metal ions such as arsenic and lead is increased to >99.8%, and the microbial removal rate is 100%.

[0030] In some embodiments, the pumping assembly has a first-level high-pressure pump 6 and a second-level high-pressure pump 9; the first-level high-pressure pump 6 is connected between the water exchange tank 2 and the first reverse osmosis module 7; the second-level high-pressure pump 9 is connected between the first reverse osmosis module 7 and the second reverse osmosis module 10; the energy storage box 8 supplies power to the first-level high-pressure pump 6 and the second-level high-pressure pump 9; the first-level high-pressure pump 6 and the second-level high-pressure pump 9 are used to increase the water pressure, forcing water molecules to penetrate the reverse osmosis membrane against the concentration gradient to achieve fresh water separation.

[0031] In some embodiments, the output end of the second reverse osmosis module 10 is connected to the industrial building 11 through a pipeline for delivering desalinated seawater to the industrial building 11 .

[0032] In some embodiments, a water supply valve is connected to the heat exchange water tank 2 (the water supply valve is not shown in the figure); further, the water supply valve is connected to a seawater pump through a pipeline, and seawater is pumped into the heat exchange water tank through the seawater pump. A liquid level gauge is provided inside the heat exchange water tank 2; the liquid level gauge is used to monitor the upper and lower limits of the liquid level.

[0033] Thus far, various embodiments of the present invention have been described in detail. To avoid obscuring the concept of the present invention, some details well known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0034] The above-described embodiments represent only some embodiments of the present invention. Although the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the scope of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be based on the appended claims.

Claims

1. A zero-carbon seawater desalination device based on LNG cold energy, characterized in that: include: LNG cold energy utilization pipeline, solar thermal energy utilization circuit, seawater desalination pipeline, photovoltaic energy storage device and hot water exchange tank; The seawater desalination pipeline comprises a drain valve, a reverse osmosis treatment component and a pumping component, wherein the drain valve and the input end of the pumping component are connected to the heat exchange water tank through a pipeline, and the reverse osmosis treatment component is connected to the output end of the pumping component; The LNG cold energy utilization pipeline and the photothermal heat energy utilization circuit are respectively connected to the heat exchange water tank, the LNG cold energy utilization pipeline is used to provide cold energy to the water exchange water tank, and the photothermal heat energy utilization circuit is used to provide heat energy to the water exchange water tank; The photovoltaic energy storage device is used to power the zero-carbon seawater desalination device based on LNG cold energy.

2. The zero-carbon seawater desalination device based on LNG cold energy according to claim 1 is characterized in that: The heat exchange water tank has a first coil and a second coil inside; The LNG cold energy utilization pipeline is connected to the first coil inside the heat exchange water tank; The photothermal heat energy utilization circuit is connected to the second coil inside the heat exchange water tank.

3. The zero-carbon seawater desalination device based on LNG cold energy according to claim 2 is characterized in that: The LNG cold energy utilization pipeline has an LNG storage tank, which is connected to the first coil inside the heat exchange water tank through a pipeline. The liquid natural gas inside the LNG storage tank is gasified and absorbs heat inside the first coil and then transported to the industrial building.

4. The zero-carbon seawater desalination device based on LNG cold energy according to claim 2 is characterized in that: The photovoltaic energy storage device has a photovoltaic component, which is a photovoltaic thermal integrated panel; the thermal energy utilization circuit has a circulation pump, and the circulation pump is connected in series with the second coil and the thermal module of the photovoltaic thermal integrated panel through a pipeline to form a circulation circuit, and the thermal energy utilization circuit is filled with a heat exchange medium.

5. The zero-carbon seawater desalination device based on LNG cold energy according to claim 4 is characterized in that: The photovoltaic module of the photovoltaic and thermal integrated panel is connected to an energy storage box, which is used to power the zero-carbon seawater desalination device based on LNG cold energy.

6. The zero-carbon seawater desalination device based on LNG cold energy according to claim 1 is characterized in that: The reverse osmosis treatment component comprises a first reverse osmosis module and a second reverse osmosis module which are sequentially connected in series through pipelines.

7. The zero-carbon seawater desalination device based on LNG cold energy according to claim 6, characterized in that: The pumping assembly comprises a primary high-pressure pump and a secondary high-pressure pump; The primary high-pressure pump is connected between the water exchange tank and the first reverse osmosis module; The secondary high-pressure pump is connected between the first reverse osmosis module and the second reverse osmosis module; The energy storage box supplies power to the primary high-pressure pump and the secondary high-pressure pump.

8. The zero-carbon seawater desalination device based on LNG cold energy according to claim 7 is characterized in that: The output end of the second reverse osmosis module is connected to the industrial building through a pipeline for delivering desalinated seawater to the industrial building.

9. The zero-carbon seawater desalination device based on LNG cold energy according to claim 1, characterized in that: The heat exchange water tank is connected with a water supply valve.

10. The zero-carbon seawater desalination device based on LNG cold energy according to claim 9, characterized in that: The water supply valve is connected to a seawater pump through a pipeline, and the seawater is pumped into the heat exchange water tank through the seawater pump.

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