A device for treating saline wastewater and a system for treating saline wastewater in a heliostat field

Abstract

The present invention discloses a device for treating saline wastewater, which comprises an evaporation container and a solar thermal evaporator. The solar thermal evaporator is arranged inside the evaporation container. The evaporation container is provided with a light-transmitting part, and light irradiates and heats the solar thermal evaporator through the light-transmitting part. The evaporation container is provided with a steam outlet and a first water inlet, and the solar thermal evaporator is connected to the first water inlet through a pipeline. By setting the solar thermal evaporator and the light-transmitting part on the evaporation container, the present invention can realize the evaporation of saline wastewater by light energy. The required light can be provided by scheduling idle heliostats, realizing the utilization of the abandoned light of the heliostats and reducing energy consumption. Moreover, the evaporation process of the saline wastewater is set in a closed evaporation container to ensure that the treatment process of the saline wastewater has no impact on the environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of wastewater treatment, and particularly relates to a device for treating saline wastewater and a system for treating saline wastewater in a heliostat field. Background Art

[0002] Solar energy and wind energy, as clean and renewable energy sources, are being increasingly applied. In particular, a new energy multi-energy complementary power station composed of solar thermal power generation technology and photovoltaic or wind power is an emerging new energy power station following photovoltaic, solar thermal, and wind power generation technologies. Due to its characteristics such as long-term energy storage, combined heat and power supply, and peak shaving, it has received extensive attention.

[0003] For tower-type solar thermal power generation, the mirror reflects sunlight, and the cleanliness of the mirror will affect the mirror reflectivity, thereby affecting the absorption of solar radiation energy. For photovoltaic power generation, the cleanliness of the glass surface also affects the power generation amount of photovoltaic power. Therefore, it is necessary to regularly clean the surfaces of heliostats and photovoltaic glass with water of relatively high purity. Moreover, in a tower-type solar thermal power station, there is a steam-water circulation system, and the water in it must also be treated. Inevitably, high-saline wastewater is generated during the process of preparing the above-mentioned water. With the continuous strengthening of environmental protection policies, environmental protection departments in various provinces do not allow the treatment of wastewater through evaporation ponds for new construction projects, and it is required that new construction projects achieve zero wastewater discharge.

[0004] Currently, the treatment processes for high-saline wastewater include mechanical recompression evaporation, multi-effect evaporation, falling film evaporation, etc. Since the concentration of high-saline wastewater from solar thermal power generation and photovoltaic power stations is much lower than that of desulfurization wastewater from thermal power plants and electroplating wastewater from electroplating factories, the above treatment processes have problems of excessive power consumption or steam consumption when treating wastewater with a relatively low salt concentration, and additional solid-liquid separation needs to be set up if solid-liquid separation is to be achieved. Summary of the Invention

[0005] In view of the problems in the background art, the object of the present invention is to provide a device for treating saline wastewater, including an evaporation container and a solar thermal evaporator, wherein the solar thermal evaporator is arranged in the evaporation container;

[0006] The evaporation container is provided with a light-transmitting part, and light irradiates and heats the solar thermal evaporator through the light-transmitting part;

[0007] The evaporation container is provided with a steam outlet and a first water inlet, and the solar thermal evaporator is connected to the first water inlet through a pipeline.

[0008] Preferably, the solar thermal evaporator includes a water spraying component and an internal flow channel. The inlet of the internal flow channel is connected to the first water inlet through a pipeline, and the outlet is connected to the water spraying component. The outlet of the water spraying component faces the outer wall surface of the solar thermal evaporator.

[0009] Preferably, it includes a water circulation component, which is connected to the evaporation container and the solar thermal evaporator, and is used to circulate and transport the saline wastewater in the evaporation container to the solar thermal evaporator;

[0010] The water circulation component is arranged outside the evaporation container. The evaporation container is provided with a water outlet, and the water circulation component is connected to the water outlet and the first water inlet.

[0011] Preferably, the solar thermal evaporator includes a plurality of vertically arranged heat absorption tubes and a water inlet distribution component, and the internal flow channel is arranged inside the heat absorption tubes;

[0012] The bottom inlets of a plurality of the heat absorption tubes are all connected to the water inlet distribution component, and the tops are all connected to the water spraying component; the water inlet distribution component is connected to the first water inlet.

[0013] Preferably, a plurality of the heat absorption tubes are arranged in a ring shape. The water inlet distribution component includes an annular water inlet pipe and a connecting pipe. The annular water inlet pipe is connected to the bottoms of each of the heat absorption tubes, and the connecting pipe connects the annular water inlet pipe and the first water inlet;

[0014] The water spraying component includes an annular water outlet pipe and a plurality of nozzles. The annular water outlet pipe is connected to the tops of each of the heat absorption tubes, and the diameter of the annular water outlet pipe is larger than the diameter of the ring formed by a plurality of the heat absorption tubes; a plurality of the nozzles are arranged circumferentially on the annular water outlet pipe and are arranged obliquely downward towards the outer pipe surface of the heat absorption tubes.

[0015] Preferably, the number of the nozzles is the same as that of the heat absorption tubes, and each nozzle correspondingly faces one heat absorption tube.

[0016] Preferably, the angle between the axis of the nozzle and the vertical direction is 30 - 70 degrees.

[0017] Preferably, it further includes a vacuum pumping system, which is arranged outside the evaporation container and is connected to the steam outlet.

[0018] Preferably, it further includes an electric heating component, which is arranged inside the evaporation container.

[0019] Preferably, the evaporation container includes a water storage tank and a cylinder body. The top of the water storage tank is open;

[0020] The cylinder body is arranged on the water storage tank. The light-transmitting part is the cylinder body, and the cylinder body is made of a light-transmitting material.

[0021] Preferably, the water storage tank is provided with a second water inlet.

[0022] Based on the same concept, the present invention also provides a heliostat field saline wastewater treatment system, including the saline wastewater treatment device described in any one of the above embodiments, and reflecting light to the saline wastewater treatment device through a heliostat.

[0023] Due to the adoption of the above technical solutions, the present invention has the following advantages and positive effects compared with the prior art:

[0024] 1. The present invention is provided with a solar thermal evaporator, and a light-transmitting part is arranged on the evaporation container, which can realize the evaporation of saline wastewater by light energy. The required light can be provided by scheduling idle heliostats, realizing the utilization of the abandoned light of the heliostat and reducing energy consumption. Moreover, the evaporation process of the saline wastewater is arranged in a closed evaporation container to ensure that the saline wastewater treatment process has no impact on the environment.

[0025] 2. The saline wastewater of the present invention first enters the internal flow channel of the solar thermal evaporator and is heated, and then is sprayed onto the outer wall surface of the solar thermal evaporator through a water spraying component for secondary heating and evaporation, so that both the inside and outside of the solar thermal evaporator are utilized, realizing the efficient utilization of the solar thermal evaporator. In addition, when the saline wastewater in the solar thermal evaporator is sprayed onto its outer wall surface, a local evaporation phenomenon will first occur at the interface between the outer wall surface and the saline wastewater, and the steam drum generated by the local evaporation isolates the saline wastewater from the outer wall surface of the solar thermal evaporator, so that the saline wastewater and the outer wall surface of the solar thermal evaporator do not directly contact, and the scaling of the saline wastewater on the outer wall surface of the solar thermal evaporator can be prevented as the saline wastewater descends.

[0026] 3. The present invention is also provided with a vacuum pumping system. On the one hand, it can pump the evaporation container to vacuum to reduce the saturation temperature of the saline wastewater and accelerate its evaporation. On the other hand, it can quickly pump out the evaporated water vapor.

[0027] 4. The present invention is also provided with a heating component, which can accelerate the treatment by using abandoned electricity such as photovoltaic or wind power or solely rely on abandoned electricity to treat saline wastewater, realizing the comprehensive utilization of energy. For example, the abandoned electricity of the heliostat field can be used to supply power to the heating component, realizing the dual utilization of the abandoned light and abandoned electricity of the heliostat field.

[0028] 5. The water storage tank of the present invention is provided with a second water inlet, and the water storage tank can store saline wastewater through the second water inlet, so that the water storage tank can be used as a buffer tank. The saline wastewater generated by cleaning the heliostat and the like can be stored in the water storage tank first, and when the heliostat is idle, the heliostat can be scheduled to supply light to the solar thermal evaporator, so that the device has the characteristics of intermittent operation.

[0029] 6. When the device operates for a long time and partial scaling occurs, since the scaling occurs in the part where the saline wastewater flows in the device, only the pumped saline wastewater needs to be replaced with a cleaning liquid (such as acid or alkali) to realize the cleaning of the whole device. Description of the Drawings

[0030] The following further elaborates on the specific embodiments of the present invention in conjunction with the accompanying drawings, where:

[0031] Figure 1 is the front view cross-sectional diagram of the salt-containing wastewater treatment device of the present invention;

[0032] Figure 2 is of the present invention Figure 1 partial schematic diagram;

[0033] Figure 3 is the top view cross-sectional diagram of the salt-containing wastewater treatment device of the present invention;

[0034] Figure 4 is the schematic diagram of the water inlet distribution component of the present invention.

[0035] Explanation of reference numerals:

[0036] 1: End cover; 2: Cylinder body; 3: Water storage tank; 4: Photo-thermal evaporator; 5: Heat absorption tube; 6: Annular water inlet pipe; 7: Cross pipe; 8: Elbow pipe; 9: Annular water outlet pipe; 10: Nozzle; 11: Steam outlet; 12: First water inlet; 13: Second water inlet; 14: Water outlet; 15: Installation interface. Specific embodiments

[0037] The following further elaborates on the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description and claims, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise ratios, only for conveniently and clearly assisting in explaining the purpose of the embodiments of the present invention.

[0038] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0039] Embodiment 1

[0040] Referring to Figures 1 to 4 , the core of the present invention is to provide a salt-containing wastewater treatment device, including an evaporation container and a photo-thermal evaporator 4. The photo-thermal evaporator 4 is arranged in the evaporation container, and the photo-thermal evaporator 4 evaporates the salt-containing wastewater through light.

[0041] The evaporation container is provided with a light-transmitting part, and light irradiates the heating photothermal evaporator 4 through the light-transmitting part. Specifically, the evaporation container includes a water storage tank 3 and a cylinder body. The top of the water storage tank 3 is open. The cylinder body is arranged on the water storage tank 3. The light-transmitting part is the cylinder body, and the cylinder body is made of a light-transmitting and non-light-absorbing material, such as glass, etc. The cylinder body includes an end cover 1 and a cylinder body 2, and both the end cover 1 and the cylinder body 2 are provided with reinforcing ribs for strengthening the structural strength. The water storage tank 3 is made of an acid- and alkali-resistant metal material.

[0042] On the side wall of the water storage tank 3 of the evaporation container, there are a first water inlet 12, a second water inlet 13 and a water outlet 14. On the end cover 1, there is a steam outlet 11. The photothermal evaporator 4 is connected to the first water inlet 12 through a pipeline. Salt-containing wastewater is conveyed to the photothermal evaporator 4 through the first water inlet 12. Salt-containing wastewater can be directly introduced into the water storage tank 3 through the second water inlet 13. The water vapor formed by the evaporation of the salt-containing wastewater by the photothermal evaporator 4 is discharged through the steam outlet 11. The water outlet 14 is arranged at the bottommost part.

[0043] The evaporation of the salt-containing wastewater by the photothermal evaporator 4 can be realized, and the required light can be provided by scheduling idle heliostats, realizing the utilization of the abandoned light of the heliostats and reducing energy consumption. Moreover, the evaporation process of the salt-containing wastewater is set in a closed evaporation container to ensure that the treatment process of the salt-containing wastewater has no impact on the environment.

[0044] The photothermal evaporator 4 includes a water spraying component and an internal flow channel. The inlet of the internal flow channel is connected to the first water inlet 12 through a pipeline, and the outlet is connected to the water spraying component. The outlet of the water spraying component faces the outer wall surface of the photothermal evaporator 4.

[0045] Specifically, the photothermal evaporator 4 includes a number of vertically arranged heat absorption tubes 5 and a water inlet distribution component. The internal flow channel is arranged inside the heat absorption tubes 5. The bottom inlets of a number of heat absorption tubes 5 are all connected to the water inlet distribution component, and the tops are all connected to the water spraying component; the water inlet distribution component is connected to the first water inlet 12. The salt-containing wastewater enters the water inlet distribution component through the first water inlet 12, and the water inlet distribution component distributes the salt-containing wastewater to each heat absorption tube 5. The salt-containing wastewater passing through each heat absorption tube 5 finally enters the water spraying component again.

[0046] A number of heat absorption tubes 5 are arranged in a ring shape. The water inlet distribution component includes an annular water inlet pipe 6 and a transfer pipe. The annular water inlet pipe 6 is connected to the bottoms of each heat absorption tube 5, and the transfer pipe connects the annular water inlet pipe 6 and the first water inlet 12. More specifically, the transfer pipe includes a cross pipe 7 and an elbow 8. The cross pipe 7 is composed of two cross-intersecting and mutually connected pipes. The cross pipe 7 is arranged in the middle of the annular water inlet pipe 6, and the four ports of the cross pipe 7 are respectively connected to four positions of the annular water inlet pipe 6. One end of the elbow 8 is connected to the lower end of the middle part of the cross pipe 7, and the other end is connected to the first water inlet 12.

[0047] The water spraying assembly includes an annular water outlet pipe 9 and a number of nozzles 10. The annular water outlet pipe 9 is communicated with the tops of the respective heat absorption pipes 5, and the diameter of the annular water outlet pipe 9 is greater than the annular diameter formed by the number of heat absorption pipes 5. The number of nozzles 10 is arranged circumferentially on the annular water outlet pipe 9 and is arranged obliquely downward towards the outer pipe surface of the heat absorption pipe 5. The number of nozzles 10 is greater than or equal to the number of heat absorption pipes 5. Preferably, the number of nozzles 10 is the same as the number of heat absorption pipes 5, and each nozzle 10 correspondingly faces one heat absorption pipe 5. The angle between the axis of the nozzle 10 and the vertical direction is 30 - 70 degrees, preferably 30 - 50 degrees.

[0048] The outer surfaces of the elbow pipe 8, the cross pipe 7, the annular water inlet pipe 6, the heat absorption pipe 5, and the annular water outlet pipe 9 are all coated with a black acid and alkali resistant coating.

[0049] The saline wastewater first enters the interior of the heat absorption pipe 5 and is heated, and then is sprayed through the nozzles 10 onto the outer wall surface of the heat absorption pipe 5 for secondary heating and evaporation, so that both the inside and outside of the heat absorption pipe 5 are utilized, realizing the efficient utilization of the solar thermal evaporator 4. In addition, when the saline wastewater in the heat absorption pipe 5 is sprayed onto its outer wall surface, local evaporation will first occur at the interface between the outer wall surface and the saline wastewater, and the steam drum generated by the local evaporation isolates the saline wastewater and the outer wall surface of the heat absorption pipe 5, so that the saline wastewater and the outer wall surface of the heat absorption pipe 5 do not directly contact, and scale formation on the outer wall surface of the heat absorption pipe 5 can be prevented as the saline wastewater descends.

[0050] The water storage tank 3 can store saline wastewater through the second water inlet 13, so that the water storage tank 3 can be used as a buffer tank. The saline wastewater generated by cleaning the heliostat and the like can be stored in the water storage tank 3 first, and when the heliostat is idle, the heliostat can be scheduled to supply light to the solar thermal evaporator 4, making the device have the characteristics of intermittent operation. Compared with the current mechanical evaporation and recompression scheme which requires a large amount of electric energy, and the multi-effect evaporation which requires a large amount of steam, the present invention realizes the comprehensive utilization of energy.

[0051] It includes a water circulation assembly that communicates with the evaporation container and the solar thermal evaporator 4 and is used to circulate the saline wastewater in the evaporation container to the solar thermal evaporator 4. Specifically, the water circulation assembly is arranged outside the evaporation container. The water circulation assembly communicates with the water outlet 14 and the first water inlet 12. The water circulation assembly can be composed of a circulation water pipe and a circulation pump arranged on the circulation water pipe, and no specific limitation is made here. Through the circulation of the water circulation assembly, the saline wastewater is continuously evaporated, and the concentration is continuously increased so that salts are precipitated and crystallized.

[0052] It also includes a vacuum pumping system, which is arranged outside the evaporation container and communicates with the steam outlet 11. The vacuum pumping system can be composed of a vacuum tube and a vacuum transfer pump arranged on the vacuum tube, and specific limitations are not made here. The vacuum pumping system, on the one hand, can evacuate the evaporation container to reduce the saturation temperature of the saline wastewater and accelerate its evaporation, and on the other hand, can quickly extract the evaporated water vapor. The vacuum pumping system is also connected with a condensation system for condensing the water vapor into liquid water.

[0053] It also includes an electric heating component, which is arranged inside the evaporation container. Specifically, a number of installation interfaces 15 for installing the electric heating component are provided on the side wall of the water storage tank 3. The electric heating component can be an electric heating tube, and the electric heating tube can be inserted into the water storage tank 3 through the installation interface 15 to complete the installation. The treatment can be accelerated by using abandoned electricity such as photovoltaic or wind power, or the saline wastewater can be treated solely by relying on abandoned electricity. When the amount of saline wastewater to be treated is large, the saline wastewater can be purified by double evaporation treatment with the solar thermal evaporator 4 and the electric heating component, realizing the comprehensive utilization of energy. For example, the abandoned electricity of the heliostat field can be used to supply power to the heating component, realizing the double utilization of the abandoned light and abandoned electricity of the heliostat field.

[0054] Embodiment 2

[0055] Another core of the present invention is to provide a saline wastewater treatment system for a heliostat field, including the saline wastewater treatment device of Embodiment 1, and the light is reflected to the saline wastewater treatment device through the heliostat. The crystallization of the saline wastewater and the separation of pure water are realized by using the abandoned light of the heliostat during certain periods in the solar thermal power station, realizing the comprehensive utilization of energy.

[0056] The working process of the present invention will be further described below:

[0057] First, the air in the evaporation container is evacuated through the vacuum pumping system, and then the saline wastewater is pumped by a water pump through the first water inlet 12, the elbow 8, the cross tube 7, the annular water inlet pipe 6 into the heat absorption tube 5, and then enters the nozzle 10 through the annular water outlet pipe 9 and is ejected. The saline wastewater flows into the water storage tank 3. After all the saline wastewater is transported to the water storage tank 3, the water circulation component is started to make the saline wastewater circulate in the water storage tank 3 and the solar thermal evaporator 4.

[0058] After the above process is established, the idle heliostats are scheduled to move their focus points to the surface of the heat absorption tube 5 to heat the saline wastewater. The saline wastewater is first heated by the inner wall surface of the heat absorption tube 5 and then sprayed onto the outer wall surface of the heat absorption tube 5 by the nozzle 10 for another heating. Since the pressure in the evaporation container is close to vacuum (as the pressure in the evaporation container decreases, the saturation temperature of the saline wastewater also decreases), when the temperature of the saline wastewater is higher than the corresponding saturation temperature, the saline wastewater begins to evaporate. The evaporated water vapor is extracted through the steam outlet 11 by the vacuum pumping system and then condensed into liquid water by the condensation system. The saline wastewater inside the water storage tank 3 starts to precipitate and crystallize as the concentration continuously increases, thus realizing the separation of the saline wastewater and zero discharge of the wastewater.

[0059] When the treatment volume of the saline wastewater is large, the electric heating component can be started to accelerate the evaporation and purification of the saline wastewater.

[0060] When scaling occurs after the device has been running for a long time, the entire device can be cleaned and descaled by pumping acid and alkali cleaning solutions through the first water inlet 12.

[0061] The present invention can make full use of the abandoned light and electricity as input energy to realize the purification treatment of saline wastewater, achieve zero discharge of wastewater, and has the characteristics of being not easily scaled and being able to be automatically cleaned after scaling.

[0062] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, provided that these changes fall within the scope of the claims of the present invention and their equivalent technologies, they still fall within the protection scope of the present invention.

Claims

1. A salt-containing wastewater treatment device, characterized in that, it includes an evaporation container and a photothermal evaporator, and the photothermal evaporator is arranged inside the evaporation container; the evaporation container is provided with a light-transmitting part, and light irradiates and heats the photothermal evaporator through the light-transmitting part; the evaporation container is provided with a steam outlet and a first water inlet, and the photothermal evaporator is connected to the first water inlet through a pipeline; the photothermal evaporator includes a water spraying component and an internal flow channel, the inlet of the internal flow channel is communicated with the first water inlet through a pipeline, the outlet is communicated with the water spraying component, and the outlet of the water spraying component faces the outer wall surface of the photothermal evaporator; the photothermal evaporator includes a number of vertically arranged heat absorption tubes, and the internal flow channel is arranged inside the heat absorption tubes.

2. The salt-containing wastewater treatment device according to claim 1, characterized in that, it includes a water circulation component, which communicates the evaporation container and the photothermal evaporator and is used for circulating and transporting the salt-containing wastewater in the evaporation container to the photothermal evaporator; the water circulation component is arranged outside the evaporation container, the evaporation container is provided with a water outlet, and the water circulation component communicates the water outlet and the first water inlet.

3. The salt-containing wastewater treatment device according to claim 1, characterized in that, the photothermal evaporator includes a water inlet distribution component; the bottom inlets of a number of the heat absorption tubes are all communicated with the water inlet distribution component, and the tops are all communicated with the water spraying component; the water inlet distribution component is communicated with the first water inlet.

4. The salt-containing wastewater treatment device according to claim 3, characterized in that, a number of the heat absorption tubes are arranged in a ring shape, the water inlet distribution component includes an annular water inlet pipe and a transfer pipe, the annular water inlet pipe is communicated with the bottoms of the respective heat absorption tubes, and the transfer pipe connects the annular water inlet pipe and the first water inlet; the water spraying component includes an annular water outlet pipe and a number of nozzles, the annular water outlet pipe is communicated with the tops of the respective heat absorption tubes, and the diameter of the annular water outlet pipe is larger than the diameter of the ring formed by a number of the heat absorption tubes; a number of the nozzles are arranged circumferentially on the annular water outlet pipe and are arranged obliquely downward and facing the outer pipe surface of the heat absorption tubes.

5. The salt-containing wastewater treatment device according to claim 1, characterized in that, it further includes a vacuum pumping system, which is arranged outside the evaporation container and communicates with the steam outlet.

6. The salt-containing wastewater treatment device according to claim 1, characterized in that, it further includes an electric heating component, which is arranged inside the evaporation container.

7. The salt-containing wastewater treatment device according to claim 1, characterized in that, the evaporation container includes a water storage tank and a cylinder body, and the top of the water storage tank is open; the cylinder body is arranged on the water storage tank, the light-transmitting part is the cylinder body, and the cylinder body is made of a light-transmitting material.

8. The salt-containing wastewater treatment device according to claim 7, characterized in that, the water storage tank is provided with a second water inlet.

9. A heliostat field salt-containing wastewater treatment system, characterized in that, it includes the salt-containing wastewater treatment device according to any one of claims 1 to 8, and light is reflected to the salt-containing wastewater treatment device by a heliostat.

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