Saline-alkali water treatment equipment applied to saline-alkali soil

Abstract

The invention relates to saline-alkali water treatment equipment applied to saline-alkali soil. The saline-alkali water treatment equipment comprises a heat energy unit, a falling film unit, a first container, a second container and a condensation unit, the heat energy unit comprises a photovoltaic panel and a heat exchange plate, and a heat exchange flow channel allowing heat supply liquid to circulate is formed in the heat exchange plate. The falling film evaporation unit comprises a shell, a water distribution tank and first heat exchange pipes, the water distribution tank and the first heat exchange pipes are arranged in the shell, a plurality of water distribution holes are formed in the bottom of the water distribution tank at intervals, and the first heat exchange pipes are arranged below the water distribution tank and communicated with the heat exchange runner. The first container is used for inputting saline-alkaline water into the water distribution tank, the second container is connected with the shell, and the second container is used for collecting concentrated saline-alkaline water. The condensation unit communicates with the shell and is used for condensing water vapor. The equipment is favorable for reducing the power consumption during evaporation and concentration treatment, and is favorable for reducing the treatment cost. Saline-alkali water drops onto the first heat exchange tube and forms an extremely thin water film on the first heat exchange tube, so that the treatment efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of saline-alkali land improvement technology, and in particular to a saline-alkali water treatment device for use in saline-alkali land. Background Technology

[0002] Saline-alkali land refers to soils that have undergone salinization or alkalization processes. Due to the high salt and alkali content, the soil's physicochemical properties are altered, primarily manifesting as soil compaction, poor structure, increased pH, and a lack of available nutrients. Severe soil salinization significantly impacts soil quality, leading to a poor ecological environment, reduced biomass, and limited crop growth.

[0003] In related technologies, methods such as rainwater infiltration and dike infiltration are used to remove saline-alkali components from the soil, which dissolve into the water to form saline-alkali water. The collected saline-alkali water is then concentrated through evaporation to separate the water for reuse. During the evaporation process, the saline-alkali water is centrally heated in pipes or containers. This method consumes a large amount of electricity, resulting in high processing costs. Furthermore, some saline-alkali components crystallize inside the pipes or containers during evaporation, making cleaning difficult and affecting heat exchange efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a saline-alkali water treatment device for saline-alkali land, which has low treatment cost and high treatment efficiency.

[0005] To achieve this objective, the present invention adopts the following technical solution: A saline-alkali water treatment device for use in saline-alkali land is provided, comprising: A thermal energy unit, comprising a photovoltaic panel and a heat exchange plate disposed on the back of the photovoltaic panel, wherein the heat exchange plate is provided with a heat exchange channel for the flow of heating liquid; A falling film evaporation unit includes a shell, a water distribution tank and a first heat exchange tube disposed within the shell. The bottom of the water distribution tank is provided with a plurality of water distribution holes spaced apart. A plurality of first heat exchange tubes are arranged below the water distribution tank, with each of the plurality of first heat exchange tubes corresponding to one of the plurality of water distribution holes. The first heat exchange tubes are bent at 180°, with the bent section of the first heat exchange tube located below the corresponding water distribution hole. The ends of the first heat exchange tubes face downwards, and the two ends of the first heat exchange tubes are respectively connected to the inlet end and the outlet end of the heat exchange channel. A first container is used to store saline water from saline-alkali land. The first container is connected to the water distribution tank and is used to input the saline water into the water distribution tank. The second container is connected to the shell. The brine water drips onto the surface of the first heat exchange tube through the water distribution hole. The brine water evaporates and concentrates to form concentrated brine water. The concentrated brine water is collected by the shell and then fed into the second container. A condensing unit is connected to the housing. Water vapor formed after the salt water evaporates is input into the condensing unit, which is used to condense the water vapor.

[0006] In one embodiment, a plurality of annular grooves are provided on the outer wall of the first heat exchange tube, and the plurality of grooves are distributed at intervals along the axial direction of the first heat exchange tube.

[0007] In one embodiment, a spiral groove is provided on the outer wall of the first heat exchange tube.

[0008] In one embodiment, the falling film evaporation unit further includes an inlet manifold communicating with the outlet end of the heat exchange channel and an outlet manifold communicating with the inlet end of the heat exchange channel. The inlet manifold and the outlet manifold are installed outside the housing. The two ends of the first heat exchange tube pass through the bottom of the housing and are respectively connected to the inlet manifold and the outlet manifold.

[0009] In one embodiment, the falling film evaporation unit further includes a plug that can be raised and lowered. Each water distribution hole is provided with a corresponding plug. The inner wall of the water distribution hole and the outer wall of the plug are spherical and fit together. The plug is selectively inserted into the water distribution hole.

[0010] In one embodiment, the outer surface of the first heat exchange tube is coated with a hydrophilic coating.

[0011] In one embodiment, the condensation unit includes a front-end condensing device, a rear-end condensing device, and a cold source circulation device. The front-end condensing device is connected to the housing, the rear-end condensing device is connected to the front-end condensing device, and the rear-end condensing device is located downstream of the front-end condensing device. Both the front-end condensing device and the rear-end condensing device are connected to the cold source circulation device. The water vapor in the front-end condensing device exchanges heat with the refrigerant in the cold source circulation device, and the water vapor in the rear-end condensing device exchanges heat with the refrigerant in the cold source circulation device.

[0012] In one embodiment, the front-end condensing device includes a first housing and a second heat exchange tube disposed within the first housing. The second heat exchange tube is reciprocally bent, with its inlet end connected to the housing and its outlet end connected to the rear-end condensing device. The first housing is provided with an air inlet and an air outlet. The cold source circulation device includes a fan disposed on the housing. The fan is used to drive air from the air inlet to the air outlet and to make the air flow over the surface of the second heat exchange tube.

[0013] In one embodiment, a third container is also included. The downstream condensing device includes multiple plate heat exchangers, each containing multiple condensing channels and refrigerant channels. The refrigerant channels and condensing channels are staggered. The inlet end of the condensing channel is connected to the upstream condensing device, and the outlet end of the condensing channel is connected to the third container. The liquid water formed after the water vapor is condensed is input into the third container. Both ends of the refrigerant channel are connected to the cold source circulation device.

[0014] In one embodiment, the plate heat exchanger includes a shell, partitions, baffles, and corrugated plates. Two partitions are arranged parallel to each other and spaced apart inside the shell, dividing the internal space of the shell into an intermediate chamber and end chambers located at opposite ends of the intermediate chamber. Baffles are provided in the end chambers, dividing the end chambers into a first distribution chamber and a second distribution chamber. The two first distribution chambers are respectively connected to the front-end condensing device and the third container. The two second distribution chambers are connected to the cold source circulation device. Multiple first distribution holes are provided through the partitions located in the first distribution chambers, and multiple second distribution holes are provided through the partitions located in the second distribution chambers. Multiple corrugated plates are distributed at intervals in the intermediate chamber, and a condensation channel or a refrigerant channel is formed between adjacent two corrugated plates. The condensation channel is connected to the first distribution hole, and the refrigerant channel is connected to the second distribution hole.

[0015] The advantages of this invention compared to the prior art are: This invention discloses a saline-alkali water treatment device for saline-alkali land. By connecting a falling film evaporation unit to a thermal energy unit, the byproducts of photovoltaic power generation are used to heat the supply liquid, providing thermal energy for the falling film evaporation unit. This method helps reduce energy consumption during evaporation and concentration, thus lowering treatment costs. By setting up a water distribution tank and a first heat exchange tube, the saline-alkali water is evenly dripped onto the first heat exchange tube through the water distribution tank, forming a very thin water film on the tube. This increases the heating surface area of ​​the saline-alkali water, thereby improving treatment efficiency. Simultaneously, the crystalline substances produced after evaporation are located on the outside of the first heat exchange tube, facilitating cleaning. Attached Figure Description

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a schematic diagram of a saline-alkali water treatment device applied to saline-alkali land according to an embodiment of the present invention.

[0018] Figure 2 This is a cross-sectional view of the heat exchange plate according to an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the front-end condensation device according to an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the downstream condensation device according to an embodiment of the present invention.

[0021] Figure 5 This is a cross-sectional view of the first section of the downstream condensation device according to an embodiment of the present invention.

[0022] Figure 6 This is a cross-sectional view of the second section of the downstream condensation device according to an embodiment of the present invention.

[0023] Figure 7 This is a schematic diagram of a falling film evaporation unit according to an embodiment of the present invention.

[0024] Figure 8 This is a cross-sectional view of the water distribution trough according to an embodiment of the present invention.

[0025] Figure 9 This is a partial schematic diagram of the first heat exchange tube according to an embodiment of the present invention.

[0026] Figure 10 This is a partial schematic diagram of the first heat exchange tube according to another embodiment of the present invention.

[0027] In the picture: 1. Thermal energy unit; 11. Photovoltaic panel; 12. Heat exchange plate; 121. Heat exchange channel; 13. Support frame; 2. Falling film evaporation unit; 21. Shell; 210. Water collection chamber; 22. Water distribution trough; 221. Water distribution hole; 23. First heat exchange tube; 231. Groove; 24. Liquid inlet collection pipe; 25. Liquid outlet collection pipe; 26. Liquid inlet pipe connector; 27. Liquid outlet pipe connector; 28. Plug; 29. ​​Drive component; 3. First container; 4. Second container; 5. Third container; 6. Front-end condenser; 61. First housing; 61 1. Air inlet; 612. Air outlet; 62. Second heat exchange tube; 7. Rear condenser; 71. Second housing; 72. Plate heat exchanger; 721. Outer shell; 722. Partition; 723. Baffle; 724. Corrugated plate; 725. First distribution chamber; 726. Second distribution chamber; 727. First distribution hole; 728. Second distribution hole; 73. Inlet connector; 74. Outlet connector; 75. Intermediate chamber; 76. Condensation channel; 77. Refrigerant channel; 8. Cold source circulation device; 81. Fan; 9. Piping. Detailed Implementation

[0028] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0029] like Figure 1 , Figure 2 and Figure 7As shown, this invention provides a saline-alkali water treatment device (hereinafter referred to as the saline-alkali water treatment device) for use in saline-alkali land, used to separate and treat saline-alkali water collected from saline-alkali land to obtain concentrated saline-alkali water and water. The saline-alkali water treatment device includes a thermal energy unit 1, a falling film evaporation unit 2, a first container 3, a second container 4, and a condensation unit. The thermal energy unit 1 provides electrical and thermal energy for the saline-alkali water treatment. The thermal energy unit 1 includes a photovoltaic panel 11 and a heat exchange plate 12. The photovoltaic panel 11 is used for solar power generation. The heat exchange plate 12 is located on the back of the photovoltaic panel 11, with the side of the photovoltaic panel 11 facing away from the sun being the back of the photovoltaic panel 11. During the power generation process, the photovoltaic panel 11 releases heat to the back of the photovoltaic panel 11, and the heat exchange plate 12 absorbs the heat emitted from the photovoltaic panel 11. The heat exchange plate 12 has a heat exchange channel 121 inside, through which a heating liquid flows. The heating liquid is water; low-temperature water absorbs heat within the heat exchange channel 121 and becomes high-temperature water. The falling film evaporation unit 2 is used for evaporating and concentrating saline-alkali water. The falling film evaporation unit 2 includes a shell 21, a water distribution tank 22, and first heat exchange tubes 23. The shell 21 is a hollow structure, and the water distribution tank 22 and the first heat exchange tubes 23 are disposed inside the shell 21. The opening of the water distribution tank 22 faces upward, and multiple water distribution holes 221 are spaced apart at the bottom of the water distribution tank 22, penetrating the bottom of the tank. Multiple first heat exchange tubes 23 are arranged below the water distribution tank 22, with each tube corresponding to one of the water distribution holes 221. The first heat exchange tubes 23 are bent, with a bending angle of 180°. The bent sections of the first heat exchange tubes 23 face upward, and the ends face downward. The bent sections of the first heat exchange tubes 23 are located below the corresponding water distribution holes 221, and there is a gap between the first heat exchange tubes 23 and the water distribution tank 22. The first heat exchange tube 23 is connected to the inlet and outlet ends of the heat exchange channel 121, respectively. The first container 3 stores saline-alkali water from the saline-alkali land. The first container 3 is connected to the water distribution tank 22 and is used to feed saline-alkali water into the water distribution tank 22. The second container 4 stores concentrated saline-alkali water and is connected to the shell 21. The saline-alkali water in the water distribution tank 22 drips onto the surface of the first heat exchange tube 23 through the water distribution holes 221. Correspondingly, the gap between the first heat exchange tube 23 and the water distribution tank 22 allows the saline-alkali water to flow. After flowing over the surface of the first heat exchange tube 23, the saline-alkali water collects at the bottom of the shell 21. The saline-alkali water exchanges heat with the heating liquid in the first heat exchange tube 23, absorbing heat and evaporating, finally yielding concentrated saline-alkali water. The concentrated saline-alkali water collects at the bottom of the shell 21. During this process, the saline-alkali components in the saline-alkali water separate from the water. The concentrated saline-alkali water collected in the shell 21 is fed into the second container 4. The condensation unit is connected to the housing 21. Water vapor formed after the salt water evaporates is input into the condensation unit, which is used to condense the water vapor. The water vapor is condensed into water so that the water can be reused.

[0030] Understandably, the saline-alkali water obtained from saline-alkali land has a low salt and alkali content, therefore it needs to be concentrated to separate the water for reuse. The untreated saline-alkali water in the first container 3 is fed into the falling film evaporator unit 2 for evaporation and concentration. The concentrated saline-alkali water is then fed into the second container 4 for storage. A circulation system is formed between the thermal energy unit 1 and the falling film evaporator unit 2, with the heating liquid circulating between them. The heating liquid is heated to high-temperature water in the heat exchange plate 12. The high-temperature water enters the falling film evaporator unit 2, where it exchanges heat with the saline-alkali water. After releasing heat, the high-temperature water cools and flows back into the heat exchange plate 12. The saline-alkali water absorbs heat and evaporates to form concentrated saline-alkali water and water vapor. The water vapor is fed into the condensation unit for condensation, and the condensed liquid water is reused. In this embodiment, by connecting the falling film evaporation unit 2 to the thermal energy unit 1, the byproducts of power generation from the photovoltaic panel 11 are used to heat the heating liquid, providing thermal energy for the falling film evaporation unit 2. This method helps reduce the power consumption during evaporation and concentration, thus reducing processing costs. By setting up a water distribution tank 22 and a first heat exchange tube 23, the brine water is evenly dripped onto the first heat exchange tube 23 through the water distribution tank 22. The brine water forms a very thin water film on the first heat exchange tube 23, which helps to increase the heating surface of the brine water and thus improve the processing efficiency. At the same time, the brine water flows through the outer surface of the first heat exchange tube 23, and the crystalline substances produced after evaporation are located on the outside of the first heat exchange tube 23, making cleaning convenient.

[0031] Specifically, refer to Figure 1 and Figure 2 As shown, the saline-alkali water treatment equipment also includes pipes 9. The heat exchange plate 12 is connected to the first heat exchange tube 23 via pipe 9. The first container 3 is connected to the water distribution tank 22 via pipe 9. The second container 4 is connected to the shell 21 via pipe 9.

[0032] The thermal energy unit 1 also includes a support frame 13 for mounting photovoltaic panels 11. Multiple photovoltaic panels 11 are arranged in an array. Each photovoltaic panel 11 has a heat exchange plate 12 on its back. The heat exchange plate 12 is a flat plate structure, with heat exchange channels 121 located inside. The heat exchange channels 121 are arranged in a reciprocating bend to form an "S" shape, thereby increasing the flow area of ​​the heat exchange channels 121. The heating liquid in all the heat exchange plates 12 is collected through pipes 9 and fed into the falling film evaporation unit 2, and the heated liquid after heat exchange is distributed through pipes 9 to the inlet ends of each heat exchange plate 12.

[0033] Specifically, refer to Figure 7As shown, the falling film evaporation unit 2 also includes an inlet collecting pipe 24 and an outlet collecting pipe 25. A water collecting chamber 210 is formed inside the shell 21, with a water distribution trough 22 located at the top of the water collecting chamber 210 and multiple first heat exchange tubes 23 located below the water distribution trough 22. The water distribution trough 22 is used to contain brine water, which drips through the water distribution holes 221 onto the curved sections of the first heat exchange tubes 23. The brine water flows downwards along the surface of the first heat exchange tubes 23. The inlet collecting pipe 24 and the outlet collecting pipe 25 are installed outside the shell 21 and are located below the shell 21. The two ends of the first heat exchange tubes 23 are connected to the inlet collecting pipe 24 and the outlet collecting pipe 25, respectively. The first heat exchange tubes 23 need to pass through the bottom of the shell 21, and a sealed connection is made between the first heat exchange tubes 23 and the shell 21. The inlet manifold 24 is connected to the outlet end of the heat exchange channel 121 via the pipe 9, allowing the heated liquid in the heat exchange plate 12 to enter the inlet manifold 24. High-temperature heating liquid enters the first heat exchange tube 23 through the inlet manifold 24. The outlet manifold 25 is connected to the inlet end of the heat exchange channel 121 via the pipe 9, allowing the low-temperature heating liquid after heat exchange to collect in the outlet manifold 25. Finally, the low-temperature heating liquid is transported back to the heat exchange plate 12 via the pipe 9. An inlet pipe connector 26 is provided on the top of the shell 21. One end of the inlet pipe connector 26 is connected to the first container 3 via the pipe 9. The other end of the inlet pipe connector 26 faces the opening of the water distribution tank 22, or extends into the water distribution tank 22. The brine in the first container 3 is input into the water distribution tank 22 via the pipe 9 and the inlet pipe connector 26. As the brine flows over the surface of the first heat exchange tube 23, it evaporates, and the resulting concentrated brine collects at the bottom of the water collection chamber 210. A liquid outlet connector 27 is provided at the bottom of the shell 21, and the liquid outlet connector 27 is connected to the water collection chamber 210. The liquid outlet connector 27 is connected to the second container 4 via a pipe 9, and the concentrated brine is sequentially transported to the second container 4 through the liquid outlet connector 27 and the pipe 9.

[0034] Specifically, refer to Figure 8As shown, the falling film evaporation unit 2 also includes a plug 28 and a drive component 29. Multiple plugs 28 are provided, each corresponding to one of multiple water distribution holes 221. Each water distribution hole 221 is provided with one plug 28, which is used for selective insertion into the corresponding water distribution hole 221. The inner wall of the water distribution hole 221 is spherical, and correspondingly, the outer wall of the plug 28 is also spherical to mate with the water distribution hole 221. The drive component 29 includes a linear motor and a connector. The plug 28 is connected to the linear motor via the connector, enabling the linear motor to drive the plug 28 to move up and down. The up and down movement of the plug 28 changes the insertion depth between the plug 28 and the water distribution hole 221. Since both the plug 28 and the water distribution hole 221 are spherical, changing the insertion depth alters the gap between the plug 28 and the water distribution hole 221, thereby controlling the dripping speed of the brine water. In practical applications, the evaporation efficiency of the saline-alkali water can be ensured by adjusting the dripping speed of the saline-alkali water.

[0035] Specifically, refer to Figure 9 As shown, a plurality of annular grooves 231 are provided on the outer wall of the first heat exchange tube 23, and the grooves 231 are distributed at intervals along the axial direction of the first heat exchange tube 23. By providing grooves 231, the flow velocity of brine water on the surface of the first heat exchange tube 23 can be reduced, thereby improving the evaporation efficiency.

[0036] In another embodiment, reference is made to Figure 10 As shown, a groove 231 is provided on the outer wall of the first heat exchange tube 23. The groove 231 is spiral-shaped, and its length extends along the axial direction of the first heat exchange tube 23. Alternatively, the groove 231 can be understood as spirally surrounding the circumference of the first heat exchange tube 23. By providing the groove 231, the flow velocity of the brine water on the surface of the first heat exchange tube 23 can be reduced, thereby improving the evaporation efficiency.

[0037] Specifically, the outer surface of the first heat exchange tube 23 is coated with a hydrophilic coating. The hydrophilic coating is a prior art technology, which has hydrophilic properties to reduce the flow rate of the brine water on the surface of the first heat exchange tube 23, thereby improving the evaporation efficiency.

[0038] Specifically, refer to Figure 1As shown, the condensation unit includes a front-end condenser 6, a rear-end condenser 7, and a cold source circulation device 8. The front-end condenser 6 is connected to the shell 21 in the falling film evaporation unit 2, so that the water vapor generated in the shell 21 is transported to the front-end condenser 6. The front-end condenser 6 is connected to the cold source circulation device 8, which contains refrigerant, which can be low-temperature air or low-temperature water. The refrigerant circulates between the cold source circulation device 8 and the front-end condenser 6 to cool the water vapor in the front-end condenser 6, i.e., to perform the first stage of condensation treatment. The rear-end condenser 7 is connected to the front-end condenser 6 and is located downstream of the front-end condenser 6. The water vapor after the first stage of condensation treatment enters the rear-end condenser 7. The rear-end condenser 7 is connected to the cold source circulation device 8, and the refrigerant circulates between the rear-end condenser 7 and the cold source circulation device 8 to cool the water vapor in the rear-end condenser 7, i.e., to perform the second stage of condensation treatment. It should be noted that the cold source circulation device 8 contains two independent refrigerant circulation systems, which act independently on the front condenser 6 and the rear condenser 7.

[0039] Specifically, refer to Figure 3 As shown, the front-end condenser 6 includes a first housing 61 and a second heat exchange tube 62. The first housing 61 is hollow, and the second heat exchange tube 62 is disposed inside the first housing 61. The second heat exchange tube 62 is flexed and bent to form an "S" shape. The inlet end of the second heat exchange tube 62 is connected to the shell 21 in the falling film evaporator unit 2 via a pipe 9, so that water vapor in the shell 21 is input into the second heat exchange tube 62 through the pipe 9. The outlet end of the second heat exchange tube 62 is connected to the rear-end condenser 7 via a pipe 9, and the water vapor after the first stage of condensation is input into the rear-end condenser 7. An air inlet 611 is provided at the top of the first housing 61, and an air outlet 612 is provided at the bottom of the first housing 61. The cold source circulation device 8 exchanges heat with the second heat exchange tube 62 through air cooling. The cold source circulation device 8 includes a fan 81, which is disposed on the first housing 61 and covers the air inlet 611. Fan 81 drives air from inlet 611 to outlet 612. After entering the first housing 61, the air flows over the surface of the second heat exchange tube 62 to exchange heat with the water vapor in the second heat exchange tube 62. It is understood that the first stage of condensation only requires appropriate cooling of the water vapor, without the need for significant condensation. Therefore, using external air as the refrigerant is sufficient to meet the needs of the first stage of condensation. Fan 81 directly drives the airflow, allowing external air to circulate between the inside and outside of the first housing 61 as the refrigerant. This cold source circulation device 8 is characterized by its simple structure and low cost.

[0040] Specifically, refer to Figure 1 , Figures 4 to 6 As shown, the saline-alkali water treatment equipment also includes a third container 5, which is used to store condensate. The downstream condensation unit 7 includes a second housing 71 and multiple plate heat exchangers 72. The second housing 71 has a hollow structure, and the multiple plate heat exchangers 72 are disposed inside the second housing 71. Multiple condensation channels 76 and multiple refrigerant channels 77 are provided inside the plate heat exchangers 72. The condensation channels 76 and refrigerant channels 77 are arranged along the width direction of the plate heat exchangers 72, and the condensation channels 76 and refrigerant channels 77 are staggered. This structure ensures that there is a refrigerant channel 77 between two adjacent condensation channels 76, or a condensation channel 76 between two adjacent refrigerant channels 77. The inlet end of the condensation channel 76 is connected to the upstream condensation unit 6, and the outlet end of the condensation channel 76 is connected to the third container 5. Both ends of the refrigerant channel 77 are connected to the cold source circulation device 8, so that the refrigerant circulates between the cold source circulation device 8 and the refrigerant channel 77. Water vapor in the front-end condenser 6 enters the condensation channel 76, where it exchanges heat with the refrigerant in the refrigerant channel 77 to achieve condensation. The resulting liquid water (condensate) is then fed into the third container 5. In this embodiment, low-temperature water is used as the refrigerant. The refrigerant circulates between the cold source circulation device 8 and the refrigerant channel 77. The cold source circulation device 8 also includes a cooling device, such as a fan 81, to cool the refrigerant that has increased in temperature as it flows back into the cold source circulation device 8. To save costs, the cold source circulation device 8 also includes a fourth container for storing the refrigerant, which is buried in the soil for natural cooling of the refrigerant.

[0041] Specifically, the plate heat exchanger 72 includes a shell 721, partitions 722, baffles 723, and corrugated plates 724. The shell 721 has a cuboid structure, with its length direction as shown in the X direction, its width direction as shown in the Y direction, and its thickness direction as shown in the Z direction. The shell 721 is hollow, and two partitions 722 are arranged inside the shell 721. The two partitions 722 are parallel and spaced apart, and are located near the two ends of the shell 721 along its length. The two partitions 722 divide the internal space of the shell 721 into an intermediate chamber 75 and two end chambers. Along the length of the shell 721, the two end chambers are located at the two ends of the intermediate chamber 75. The corrugated plates 724 have a wavy cross-section, and multiple corrugated plates 724 are arranged at intervals along the width direction of the shell 721 within the intermediate chamber 75, forming a condensation channel 76 or a refrigerant channel 77 between adjacent corrugated plates 724. The two ends of the corrugated plate 724 along its length are connected to two partitions 722, and the two ends of the corrugated plate 724 along its width are connected to two inner walls of the outer shell 721. Each end chamber is equipped with a baffle 723, which divides the end chamber into a first distribution chamber 725 and a second distribution chamber 726. The first distribution chamber 725 and the second distribution chamber 726 are arranged along the thickness direction of the outer shell 721. Multiple first distribution holes 727 are provided through the partition 722 in the first distribution chamber 725, each corresponding to a condensation channel 76 and communicating with it. Multiple second distribution holes 728 are provided through the partition 722 in the second distribution chamber 726, each corresponding to a refrigerant channel 77 and communicating with it. The first distribution chamber 725 serves to collect water vapor and condensate. The outer casing 721 extends vertically along its length. Two inlet connectors 73 are located at the top of the casing 721, and two outlet connectors 74 are located at the bottom. The two inlet connectors 73 are connected to the first distribution chamber 725 and the second distribution chamber 726 located at the top of the casing 721, respectively. The two outlet connectors 74 are connected to the first distribution chamber 725 and the second distribution chamber 726 located at the bottom of the casing 721, respectively. All inlet connectors 73 connected to the first distribution chamber 725 are connected to the second heat exchange tube 62 in the front-end condensing device 6 via pipe 9. All outlet connectors 74 connected to the first distribution chamber 725 are connected to the third container 5 via pipe 9. Water vapor output from the front-end condensing device 6 enters the condensation channel 76 sequentially through pipe 9, inlet connectors 73, and the top first distribution chamber 725. Liquid water produced after condensation sequentially enters the third container 5 through the bottom first distribution chamber 725, outlet connectors 74, and pipe 9.Similarly, all inlet connectors 73 connected to the second distribution chamber 726 are connected to the outlet end of the cold source circulation device 8 via pipe 9. All outlet connectors 74 connected to the second distribution chamber 726 are connected to the inlet end of the cold source circulation device 8 via pipe 9. The low-temperature refrigerant in the cold source circulation device 8 enters the refrigerant channel 77 through pipe 9, inlet connectors 73, and the top second distribution chamber 726. The refrigerant whose temperature has increased after heat exchange is sequentially returned to the cold source circulation device 8 through the bottom second distribution chamber 726, outlet connectors 74, and pipe 9.

[0042] In this embodiment, the input points for water vapor and refrigerant entering the plate heat exchanger 72 are integrated at the top of the outer shell 721, while the output points for liquid water and refrigerant exiting the plate heat exchanger 72 are integrated at the bottom of the outer shell 721, making the overall structure of the plate heat exchanger 72 compact. The condensation channel 76 and refrigerant channel 77 are densely and compactly distributed, resulting in high heat exchange efficiency.

[0043] Specifically, the saline-alkali water treatment equipment also includes a water pump and a reheating device. A water pump is installed on pipe 9 to drive the flow of the heating liquid, saline-alkali water, condensate, or refrigerant within pipe 9. The reheating device includes a fifth container and an electric heater disposed within the fifth container. The electric heater is electrically connected to the photovoltaic panel 11 so that the photovoltaic panel 11 can supply power to the electric heater. The reheating device is located between the heat exchange plate 12 and the inlet end of the first heat exchange tube 23. The reheating device is used to reheat the heating liquid output from the heat exchange plate 12 to compensate for insufficient heating of the heating liquid in the heat exchange plate 12, thus ensuring the evaporation efficiency of the saline-alkali water in the falling film evaporation unit 2.

[0044] The beneficial effects of this embodiment are as follows: By connecting the falling film evaporation unit 2 to the thermal energy unit 1, the byproducts of power generation from the photovoltaic panel 11 are used to heat the heating liquid, providing thermal energy for the falling film evaporation unit 2. This method helps reduce the power consumption during evaporation and concentration, thus reducing processing costs. By setting up a water distribution tank 22 and a first heat exchange tube 23, the brine water is evenly dripped onto the first heat exchange tube 23 through the water distribution tank 22. The brine water forms a very thin water film on the first heat exchange tube 23, which helps to increase the heating surface of the brine water and thus improves the processing efficiency. At the same time, the brine water flows through the outer surface of the first heat exchange tube 23, and the crystalline substances produced after evaporation are located on the outside of the first heat exchange tube 23, making cleaning convenient.

[0045] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A saline-alkali water treatment device for use in saline-alkali land, characterized in that, include: A thermal energy unit, comprising a photovoltaic panel and a heat exchange plate disposed on the back of the photovoltaic panel, wherein the heat exchange plate is provided with a heat exchange channel for the flow of heating liquid; A falling film evaporation unit includes a shell, a water distribution tank and a first heat exchange tube disposed within the shell. The bottom of the water distribution tank is provided with a plurality of water distribution holes spaced apart. A plurality of first heat exchange tubes are arranged below the water distribution tank, with each of the plurality of first heat exchange tubes corresponding to one of the plurality of water distribution holes. The first heat exchange tubes are bent at 180°, with the bent section of the first heat exchange tube located below the corresponding water distribution hole. The ends of the first heat exchange tubes face downwards, and the two ends of the first heat exchange tubes are respectively connected to the inlet end and the outlet end of the heat exchange channel. A first container is used to store saline water from saline-alkali land. The first container is connected to the water distribution tank and is used to input the saline water into the water distribution tank. The second container is connected to the shell. The brine water drips onto the surface of the first heat exchange tube through the water distribution hole. The brine water evaporates and concentrates to form concentrated brine water. The concentrated brine water is collected by the shell and then fed into the second container. A condensing unit is connected to the housing. Water vapor formed after the salt water evaporates is input into the condensing unit, which is used to condense the water vapor.

2. The saline-alkali water treatment equipment applied to saline-alkali land according to claim 1, characterized in that, The outer wall of the first heat exchange tube is provided with a plurality of annular grooves, which are distributed at intervals along the axial direction of the first heat exchange tube.

3. The saline-alkali water treatment equipment applied to saline-alkali land according to claim 1, characterized in that, The outer wall of the first heat exchange tube is provided with a spiral groove.

4. The saline-alkali water treatment equipment applied to saline-alkali land according to claim 1, characterized in that, The falling film evaporation unit further includes an inlet manifold connected to the outlet end of the heat exchange channel and an outlet manifold connected to the inlet end of the heat exchange channel. The inlet manifold and the outlet manifold are installed outside the housing. The two ends of the first heat exchange tube pass through the bottom of the housing and are connected to the inlet manifold and the outlet manifold, respectively.

5. The saline-alkali water treatment equipment applied to saline-alkali land according to claim 1, characterized in that, The falling film evaporation unit also includes a liftable plug. Each water distribution hole is provided with a corresponding plug. The inner wall of the water distribution hole and the outer wall of the plug are spherical and fit together. The plug is selectively inserted into the water distribution hole.

6. The saline-alkali water treatment equipment applied to saline-alkali land according to claim 1, characterized in that, The outer surface of the first heat exchange tube is coated with a hydrophilic coating.

7. The saline-alkali water treatment equipment applied to saline-alkali land according to any one of claims 1 to 6, characterized in that, The condensation unit includes a front-end condensing device, a rear-end condensing device, and a cold source circulation device. The front-end condensing device is connected to the housing, and the rear-end condensing device is connected to the front-end condensing device, with the rear-end condensing device located downstream of the front-end condensing device. Both the front-end and rear-end condensing devices are connected to the cold source circulation device. The water vapor in the front-end condensing device exchanges heat with the refrigerant in the cold source circulation device, and the water vapor in the rear-end condensing device exchanges heat with the refrigerant in the cold source circulation device.

8. The saline-alkali water treatment equipment for saline-alkali land according to claim 7, characterized in that, The front-end condensing device includes a first housing and a second heat exchange tube disposed within the first housing. The second heat exchange tube is arranged in a reciprocating bend configuration. The inlet end of the second heat exchange tube is connected to the housing, and the outlet end of the second heat exchange tube is connected to the rear-end condensing device. The first housing is provided with an air inlet and an air outlet. The cold source circulation device includes a fan disposed on the housing. The fan is used to drive air from the air inlet to the air outlet and to make the air flow over the surface of the second heat exchange tube.

9. The saline-alkali water treatment equipment applied to saline-alkali land according to claim 7, characterized in that, It also includes a third container. The downstream condensing device includes multiple plate heat exchangers. Each plate heat exchanger is provided with multiple condensing channels and refrigerant channels. The refrigerant channels and condensing channels are distributed alternately. The inlet end of the condensing channel is connected to the upstream condensing device, and the outlet end of the condensing channel is connected to the third container. The liquid water formed after the water vapor is condensed is input into the third container. Both ends of the refrigerant channel are connected to the cold source circulation device.

10. The saline-alkali water treatment equipment applied to saline-alkali land according to claim 9, characterized in that, The plate heat exchanger includes a shell, partitions, baffles, and corrugated plates. Two partitions are arranged parallel to each other and spaced apart inside the shell, dividing the internal space of the shell into an intermediate chamber and end chambers located at opposite ends of the intermediate chamber. Baffles are provided in the end chambers, dividing the end chambers into a first distribution chamber and a second distribution chamber. The two first distribution chambers are respectively connected to the front-end condensing device and the third container. The two second distribution chambers are connected to the cold source circulation device. Multiple first distribution holes are provided through the partitions located in the first distribution chambers, and multiple second distribution holes are provided through the partitions located in the second distribution chambers. Multiple corrugated plates are distributed at intervals in the intermediate chamber, and a condensation channel or a refrigerant channel is formed between adjacent two corrugated plates. The condensation channel is connected to the first distribution hole, and the refrigerant channel is connected to the second distribution hole.

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