Water and heat simultaneous production system

Abstract

The invention discloses a water and heat simultaneous production system which comprises a steam turbine, a water and heat simultaneous production unit, an absorption heat pump and a flash tank, and the absorption heat pump comprises a generator, a first evaporator, an absorber and a condenser; an inlet of the steam turbine is connected with a high-pressure steam pipeline, an outlet of the steam turbine is connected with a first steam extraction pipeline and a second steam extraction pipeline, a high-temperature heat source inlet of the water-heat co-production unit is connected with the first steam extraction pipeline, a strong brine discharge pipeline of the water-heat co-production unit is connected with an inlet of the flash tank, and a steam outlet of the flash tank is connected with an inlet of the first evaporator. An outlet of the first evaporator is connected with an inlet of a condenser of the water-heat simultaneous production unit through a pipeline; the absorber is provided with a to-be-heated fluid inlet, the condenser is provided with a to-be-heated fluid outlet, and the absorber and the condenser are communicated through a pipeline so that to-be-heated fluid flowing out of the absorber can flow into the condenser and flow out of the to-be-heated fluid outlet. The second steam extraction pipeline is connected with an inlet of the generator. The waste heat of the strong brine can be fully utilized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of seawater desalination, and in particular to a water and heat co-production system. BACKGROUND

[0002] Seawater desalination is a technology for generating fresh water through multi-stage flash distillation (MSF), multi-effect distillation (MED) or reverse osmosis (RO) and the like. Among them, the multi-stage flash distillation and multi-effect distillation technologies have a high water production in seawater desalination, but these two technologies generally have the problem of a large amount of waste heat energy.

[0003] Specifically, in these two technologies, the heat energy mainly comes from high-temperature steam for driving the flash distillation and distillation processes. However, the concentrated brine generated in the flash distillation and distillation processes has a high temperature, and is directly discharged into the sea without being utilized, resulting in a low energy efficiency of the seawater desalination system and a high cost of water production. SUMMARY

[0004] In view of the above problems, the present application provides a water and heat co-production system to achieve the purpose of fully utilizing the waste heat of concentrated brine and improving the energy efficiency of the seawater desalination system. The specific scheme is as follows:

[0005] The present application provides a water and heat co-production system, comprising: a steam turbine, a water and heat co-production unit, an absorption heat pump and a flash tank, wherein the absorption heat pump comprises a generator, a first evaporator, an absorber and a condenser;

[0006] The inlet of the steam turbine is connected to a high-pressure steam pipeline, the outlet of the steam turbine is connected to a first steam extraction pipeline and a second steam extraction pipeline, the high-temperature heat source inlet of the water and heat co-production unit is connected to the first steam extraction pipeline, the concentrated brine discharge pipeline of the water and heat co-production unit is connected to the inlet of the flash tank, the steam outlet of the flash tank is connected to the inlet of the first evaporator, and the outlet of the first evaporator is connected to the inlet of the condenser of the water and heat co-production unit through a pipeline;

[0007] The absorber is provided with a to-be-heated fluid inlet, the condenser is provided with a to-be-heated fluid outlet, and the absorber and the condenser are connected through a pipeline to make the to-be-heated fluid flowing out of the absorber flow into the condenser and flow out of the to-be-heated fluid outlet;

[0008] The second steam extraction pipeline is connected to the inlet of the generator.

[0009] In a possible implementation, the fresh water discharge pipeline of the water and heat co-production unit is connected to the to-be-heated fluid inlet.

[0010] In a possible implementation, a first three-way valve is arranged on the fresh water discharge pipeline, a second three-way valve is arranged on the to-be-heated fluid inlet, and the first three-way valve and the second three-way valve are connected through a fresh water conveying pipeline.

[0011] In one possible implementation, the hydrothermal co-production unit is a multi-effect distillation unit, which includes multiple evaporators and condensers connected in series, and the condenser connected to the outlet of the first evaporator is the last stage of the multi-effect distillation unit.

[0012] In one possible implementation, the flash tank includes at least three flash units connected in series, with the pressure of each flash unit decreasing progressively. The inlet of the first flash unit is connected to a concentrated brine discharge pipeline, and the concentrated brine outlet of the last flash unit is connected to a concentrated brine recovery pipeline. The steam outlets of each flash unit are connected to the inlet of the first evaporator via a converging pipeline, and a steam purification device is installed on the converging pipeline to remove salt mist and impurities from the steam, thereby preventing corrosion of the heat exchange tubes inside the first evaporator.

[0013] In one possible implementation, a preheating heat exchanger is also included, the flash tank further having a seawater inlet for inputting seawater, the concentrated brine outlet of the final flash unit being connected to the hot-side inlet of the preheating heat exchanger, the cold-side inlet of the preheating heat exchanger being used for inputting seawater at ambient temperature, and the cold-side outlet of the preheating heat exchanger being connected to the seawater inlet.

[0014] In one possible implementation, a salinity detection device is installed on the concentrated brine recovery pipeline, and a flow regulating valve is installed at the seawater inlet. When the salinity of the concentrated brine detected by the salinity detection device exceeds a preset threshold, the flow regulating valve is opened to a first opening degree; when the salinity of the concentrated brine detected by the salinity detection device does not exceed the preset threshold, the flow regulating valve is opened to a second opening degree; the first opening degree is greater than the second opening degree.

[0015] In one possible implementation, the hydro-thermal co-production unit further includes a seawater pretreatment unit, which includes a quartz sand filter, a security filter, and a scale inhibitor addition device connected in series. The inlet of the seawater pretreatment unit is an ambient temperature seawater input, and the outlet of the seawater pretreatment unit is connected to the seawater inlet of the hydro-thermal co-production unit.

[0016] In one possible implementation, the hydro-thermal co-production unit further includes a seawater preheating unit. The hot-side inlet of the seawater preheating unit is connected to the outlet pipe of the generator, the cold-side inlet of the seawater preheating unit is the input end of ambient temperature seawater, and the cold-side outlet of the seawater preheating unit is connected to the seawater inlet of the hydro-thermal co-production unit.

[0017] In one possible implementation, the hydrothermal co-production unit is a multi-effect distillation unit, which includes multiple evaporators and condensers connected in series, and the condenser connected to the outlet of the first evaporator is the penultimate stage of the multi-effect distillation unit.

[0018] The hydrothermal co-production system provided in this application, using the above technical solution, includes: a steam turbine, a hydrothermal co-production unit, an absorption heat pump, and a flash tank. The absorption heat pump includes a generator, a first evaporator, an absorber, and a condenser. The inlet of the steam turbine is connected to a high-pressure steam pipeline, and the outlet of the steam turbine is connected to a first extraction steam pipeline and a second extraction steam pipeline. The high-temperature heat source inlet of the hydrothermal co-production unit is connected to the first extraction steam pipeline. The concentrated brine discharge pipeline of the hydrothermal co-production unit is connected to the inlet of the flash tank. The steam outlet of the flash tank is connected to the inlet of the first evaporator, and the outlet of the first evaporator is connected to the inlet of the condenser of the hydrothermal co-production unit via a pipeline. The absorber has an inlet for the fluid to be heated, and the condenser has an outlet for the fluid to be heated. The absorber and the condenser are connected by a pipeline so that the fluid to be heated flowing out of the absorber flows into the condenser and out of the outlet for the fluid to be heated. The second extraction steam pipeline is connected to the inlet of the generator. This invention has at least the following effects:

[0019] 1. This application can recover the waste heat of concentrated brine discharged from the hydrothermal co-production unit and use it to heat the fluid to be heated, so that the low-grade heat energy (the heat energy of the discharged concentrated brine) that was originally directly discharged can be utilized, effectively improving the energy utilization rate of the system, avoiding heat waste, and further reducing heating costs.

[0020] 2. This invention utilizes a second extraction steam pipeline to introduce a portion of the high-pressure, high-temperature steam from the turbine into the absorption heat pump, allowing both the absorption heat pump and the hydro-thermal co-production unit to use the same heat source, resulting in a simple structure. Simultaneously, by utilizing the waste heat from the concentrated brine discharged from the hydro-thermal co-production unit to heat the fluid to be heated, the absorption heat pump can simultaneously utilize both the waste heat from the concentrated brine and the high-pressure, high-temperature steam as heat sources. Compared to methods that rely solely on high-pressure, high-temperature steam to heat the fluid, this reduces the extraction of high-pressure, high-temperature steam, allowing more of it to be used for power generation or freshwater production.

[0021] 3. This invention employs an indirect heat exchange method to recover waste heat from concentrated brine. Specifically, the concentrated brine is converted into steam in a flash tank, and the steam then enters the first evaporator of the absorption heat pump, where it condenses and releases heat. This avoids corrosion of the inner surface of the first evaporator caused by the concentrated brine directly entering it. Furthermore, the condensate formed in the first evaporator flows back to the condenser within the hydro-thermal co-production unit, which helps improve the water production capacity of the unit and reduces the required heat exchange area for the same water production. This method of recovering waste heat from concentrated brine is applicable not only to hydro-thermal co-production units but also to multi-stage flash evaporation and multi-effect distillation seawater desalination units.

[0022] 4. This invention reduces the heat exchange area requirement of hydro-thermal power plants by introducing an absorption heat pump to recover waste heat from concentrated brine. By rationally matching the increased investment in the absorption heat pump with the cost savings from the reduced heat exchange area, the overall investment structure of the system is optimized, further enhancing the system's economic feasibility. Attached Figure Description

[0023] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0024] Figure 1 This application provides a schematic diagram of the structure of a hydrothermal co-production system;

[0025] Figure 2 A schematic diagram of another hydrothermal co-production system provided in this application;

[0026] Figure 3 A schematic diagram of another hydrothermal co-production system provided in this application;

[0027] Figure 4 A schematic diagram of another hydrothermal co-production system provided in this application.

[0028] The annotations in the attached figures are explained as follows:

[0029] 1. High-pressure steam pipeline; 2. Steam turbine; 3. First extraction steam pipeline; 4. Second extraction steam pipeline; 5. Hydro-thermal co-production unit; 6. Freshwater discharge pipeline; 7. Seawater inlet; 8. Concentrated brine discharge pipeline; 9. Absorption heat pump; 10. Generator; 11. First evaporator; 12. Absorber; 13. Condenser; 14. Inlet of fluid to be heated; 15. Outlet of fluid to be heated; 16. Flash tank; 17. Steam outlet; 18. In-unit condenser; 19. Concentrated brine recovery pipeline; 20. Preheating heat exchanger; 21. Seawater preheating unit. Detailed Implementation

[0030] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the scope of this application.

[0031] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0032] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0033] like Figure 1 As shown, an embodiment of the present invention provides a hydrothermal co-production system, which may include: a steam turbine 2, a hydrothermal co-production unit 5, an absorption heat pump 9 and a flash tank 16. The absorption heat pump 9 includes a generator 10, a first evaporator 11, an absorber 12 and a condenser 13.

[0034] The inlet of the steam turbine 2 is connected to the high-pressure steam pipeline 1, and the outlet of the steam turbine 2 is connected to the first extraction steam pipeline 3 and the second extraction steam pipeline 4. The high-temperature heat source inlet of the hydro-thermal co-production unit 5 is connected to the first extraction steam pipeline 3. The concentrated brine discharge pipeline 8 of the hydro-thermal co-production unit 5 is connected to the inlet of the flash tank 16. The steam outlet 17 of the flash tank 16 is connected to the inlet of the first evaporator 11. The outlet of the first evaporator 11 is connected to the inlet of the condenser 18 within the hydro-thermal co-production unit 5 through a pipeline.

[0035] The absorber 12 is provided with a fluid inlet 14 to be heated, and the condenser 13 is provided with a fluid outlet 15 to be heated. The absorber 12 and the condenser 13 are connected by a pipe so that the fluid to be heated flowing out of the absorber 12 flows into the condenser 13 and flows out from the fluid outlet 15 to be heated.

[0036] The second extraction steam line 4 is connected to the inlet of the generator 10.

[0037] The generator 10 is a device that uses an external heat source to heat the refrigerant in the absorbent solution to evaporate and separate it, thereby generating high-purity refrigerant vapor. It is equivalent to a "virtual compressor" in the absorption system, providing high-pressure refrigerant vapor to the system.

[0038] The first evaporator 11 is a device in which liquid refrigerant absorbs heat from the medium being cooled under low pressure and evaporates into low-temperature, low-pressure steam to achieve the purpose of refrigeration / heating. It is the output port of the absorption system for cold / heat.

[0039] The absorber 12 is a device that uses the strong adsorption properties of the absorbent solution to absorb low-pressure refrigerant vapor from the first evaporator while maintaining a low-pressure environment in the system. Together with the generator, it forms an absorption-regeneration cycle.

[0040] The condenser 13 is a heat exchange device that cools the high-temperature and high-pressure refrigerant vapor generated by the generator into a liquid state while releasing the latent heat of phase change.

[0041] Among them, the high-pressure steam in high-pressure steam pipeline 1 has a high temperature and belongs to high-pressure high-temperature steam. It can come from various sources, such as: high-pressure steam generated by nuclear power plant power generation; high-pressure steam generated by coal / natural gas combustion in thermal power plant boilers; and surplus high-pressure steam generated by industrial boilers and chemical plants.

[0042] High-pressure steam in high-pressure steam pipeline 1 drives turbine 2 to rotate, thereby driving generator to produce electrical energy or transferring kinetic energy to equipment that requires kinetic energy (e.g., driving water pump to lift fresh water produced by hydro-thermal co-production unit 5 to a higher position for energy storage). Part of the high-pressure, high-temperature steam passing through turbine 2 enters the high-temperature heat source inlet of hydro-thermal co-production unit 5 through first extraction steam pipeline 3, and another part of the high-pressure, high-temperature steam enters generator 10 through second extraction steam pipeline 4.

[0043] The hydro-thermal co-production unit 5 can utilize high-pressure, high-temperature steam as heat energy to desalinate seawater and produce high-temperature fresh water. Since the concentrated brine discharged from the concentrated brine discharge pipe 8 of the hydro-thermal co-production unit 5 also has a high temperature, to recover this energy, this application inputs the high-temperature concentrated brine into the flash tank 16 to generate high-temperature steam, which is then input into the inlet of the first evaporator 11 through the steam outlet 17 of the flash tank 16. This utilizes the high-temperature steam generated by the high-temperature concentrated brine to provide heat for the absorption heat pump 9. The high-temperature steam entering the first evaporator 11 is cooled and becomes fresh water. This application can input the fresh water discharged from the first evaporator 11 into the unit's condenser 18, and finally discharge it through the fresh water discharge pipe 6 of the hydro-thermal co-production unit 5.

[0044] The hydrothermal co-production unit 5 is a multi-effect distillation unit, which includes multiple evaporators and condensers connected in series. Optionally, the in-unit condenser 18 connected to the outlet of the first evaporator 11 is the last stage of the multi-effect distillation unit; or, the in-unit condenser 18 connected to the outlet of the first evaporator 11 is the penultimate stage of the multi-effect distillation unit.

[0045] When the condenser 18 connected to the outlet of the first evaporator 11 is the last stage of the multi-effect distillation unit, this application can introduce the fresh water discharged from the first evaporator 11 into the hydrothermal co-production unit 5 without intruding into or changing the original internal structure and thermal balance of the multi-effect distillation unit.

[0046] When the condenser 18 connected to the outlet of the first evaporator 11 is the penultimate stage of the multi-effect distillation unit, this application can use the higher-temperature fresh water discharged from the first evaporator 11 as a heat source to heat the lower-temperature feed seawater from the previous effect. Specifically, a complete effect in a multi-effect distillation unit includes an evaporator (responsible for heating seawater to evaporate it) and a condenser (responsible for cooling the steam generated in the previous effect, condensing it into fresh water, and releasing heat). The first effect (initial effect) has the highest temperature and pressure, which then decreases progressively, with the last effect (final effect) having the lowest temperature and pressure. The previous effect is the one located before the current effect in the energy flow direction. Assuming this multi-effect distillation unit has N effects, the penultimate stage is the (N-1)th effect, and the last stage (final effect) is the Nth effect. In this application, the condensate (high-temperature water) of the flash steam from the first evaporator 11 is introduced into the condenser of the (N-1)th effect. The condenser of the (N-1)th effect cools the secondary steam from the previous effect (i.e., the N-2th effect), causing it to condense into fresh water. Therefore, the condenser of the (N-1)th effect releases a large amount of condensation heat. When the in-unit condenser 18 connected to the outlet of the first evaporator 11 is the penultimate stage of the multi-effect distillation unit, high-temperature flash condensate can flow through this condenser of the (N-1)th effect, preheating the feed seawater that is about to enter the (N-1)th effect evaporator, or replacing some of the heat that would normally be provided by the steam from the previous effect (the N-2th effect).

[0047] Optionally, the fluid to be heated can be heating return water or domestic hot water preheating water.

[0048] In this way, this application can use the high-temperature concentrated brine discharged from the concentrated brine discharge pipe 8 of the hydrothermal co-generation unit 5 to heat the heating return water or domestic hot water preheating water, thereby recovering the heat energy of the high-temperature concentrated brine.

[0049] The present invention has at least the following effects:

[0050] 1. This application can recover the waste heat of concentrated brine discharged from the hydrothermal co-production unit and use it to heat the fluid to be heated, so that the low-grade heat energy (the heat energy of the discharged concentrated brine) that was originally directly discharged can be utilized, effectively improving the energy utilization rate of the system, avoiding heat waste, and further reducing heating costs.

[0051] 2. This invention utilizes the second extraction steam pipeline 4 to introduce a portion of the high-pressure, high-temperature steam from the turbine 2 into the absorption heat pump 9, allowing both the absorption heat pump 9 and the hydro-thermal co-production unit 5 to use the same heat source, resulting in a simple structure. Simultaneously, by utilizing the waste heat from the concentrated brine discharged from the hydro-thermal co-production unit to heat the fluid to be heated, the absorption heat pump 9 can simultaneously utilize both the waste heat from the concentrated brine and the high-pressure, high-temperature steam as heat sources. Compared to heating the fluid using only high-pressure, high-temperature steam, this method reduces the extraction of high-pressure, high-temperature steam, allowing more of the steam to be used for power generation or freshwater production.

[0052] 3. This invention employs an indirect heat exchange method to recover waste heat from concentrated brine. Specifically, the concentrated brine is converted into steam in the flash tank 16, and the steam then enters the evaporator of the absorption heat pump, where it condenses and releases heat. This avoids corrosion of the evaporator's inner surface caused by the concentrated brine directly entering the evaporator. Furthermore, the condensate formed by the steam condensation in the evaporator flows back to the condenser 18 within the hydro-thermal co-production unit 5, which helps improve the water production capacity of the hydro-thermal co-production unit and reduces the required heat exchange area for the same water production. This concentrated brine waste heat recovery method is applicable not only to hydro-thermal co-production units but also to multi-stage flash evaporation and multi-effect distillation seawater desalination units.

[0053] 4. This invention reduces the heat exchange area requirement of hydro-thermal power plants by introducing an absorption heat pump to recover waste heat from concentrated brine. By rationally matching the increased investment in the absorption heat pump with the cost savings from the reduced heat exchange area, the overall investment structure of the system is optimized, further enhancing the system's economic feasibility.

[0054] like Figure 2 As shown, in another embodiment of this application, the freshwater discharge pipeline 6 of the hydrothermal co-production unit 5 is connected to the inlet 14 of the fluid to be heated.

[0055] In this way, the freshwater produced by the hydro-heat co-generation unit 5 can flow into the absorption heat pump 9 through the hot-to-heat fluid inlet 14, absorb heat through the absorber 12 and condenser 13 to raise its temperature, and then be transferred to the hydro-heat demand end through the hot-to-heat fluid outlet 15. Specifically, the hydro-heat demand end can separate the freshwater and heat according to usage requirements, and then use the freshwater and heat separately. The simultaneous transfer of hydro-heat through the hot-to-heat fluid outlet 15 achieves simultaneous hydro-heat transfer, improving transfer efficiency.

[0056] Optionally, a first three-way valve is provided on the freshwater discharge pipeline 6, and a second three-way valve is provided on the inlet 14 of the fluid to be heated. The first three-way valve and the second three-way valve are connected by a freshwater delivery pipeline.

[0057] The first and second three-way valves can be used to switch the transmission path of freshwater flowing out of freshwater discharge pipe 6. The first three-way valve can be used to transfer freshwater from freshwater discharge pipe 6 to a freshwater delivery pipe or other pipes. The second three-way valve can be used to transfer freshwater from the freshwater delivery pipe to absorber 12 or to transfer other fluids to be heated to absorber 12. For example, during the heating season, by closing the freshwater delivery pipe using the first and second three-way valves, heating network water (i.e., heating water, not freshwater) can be input into absorber 12 for heat absorption, achieving... Figure 1 The flow direction is shown. During the non-heating season, the freshwater delivery pipeline is opened through the first three-way valve and the second three-way valve, and the freshwater flowing out of the freshwater discharge pipeline 6 is input into the absorber 12 for heat absorption, achieving the desired effect. Figure 2 The flow direction is shown.

[0058] Optionally, in another optional embodiment of the present invention, the flash tank 16 includes at least three flash units connected in series, with the pressure of each flash unit decreasing progressively. The inlet of the first-stage flash unit is connected to the concentrated brine discharge pipeline 8, such as... Figure 3 As shown, the concentrated brine outlet of the final flash unit is connected to the concentrated brine recovery pipeline 19. The steam outlets of each flash unit are connected to the inlet of the first evaporator 11 through a collection pipeline. A steam purification device is installed on the collection pipeline to remove salt mist and impurities from the steam and prevent corrosion of the heat exchange tubes inside the first evaporator 11.

[0059] By using at least three flash evaporation units connected in series, the flash tank 16 of this application can effectively increase the amount of steam generated from high-temperature concentrated brine, thereby increasing the heat recovered from the high-temperature concentrated brine. Simultaneously, a steam purification device can remove salt mist and impurities from the steam, preventing corrosion of the internal heat exchange tubes of the first evaporator 11.

[0060] Furthermore, such as Figure 3 As shown, the hydrothermal co-production system provided in this application embodiment may further include a preheating heat exchanger 20. The flash tank 16 also has a seawater inlet for inputting seawater. The concentrated brine outlet of the final flash unit is connected to the hot side inlet of the preheating heat exchanger 20. The cold side inlet of the preheating heat exchanger is used to input seawater at ambient temperature. The cold side outlet of the preheating heat exchanger is connected to the seawater inlet.

[0061] In some cases, the concentration of the brine discharged from the brine discharge pipe 8 is too high, making it difficult to generate steam. In such cases, seawater at ambient temperature can be introduced to dilute the brine. Since the seawater temperature is low, the waste heat from the brine discharged from the outlet of the final flash unit can be used to heat the seawater through the preheating heat exchanger 20. In this way, the waste heat from the brine discharged from the outlet of the final flash unit of the flash tank 16 is further recovered, and the steam output can be increased without the need for an additional heat source, thereby improving the waste heat recovery rate of the brine discharged from the brine discharge pipe 8.

[0062] Furthermore, a salinity detection device is installed on the concentrated brine recovery pipeline 19, and a flow regulating valve is installed at the seawater inlet. When the salinity of the concentrated brine detected by the salinity detection device exceeds a preset threshold, the flow regulating valve opens to a first opening degree; when the salinity of the concentrated brine detected by the salinity detection device does not exceed the preset threshold, the flow regulating valve opens to a second opening degree; the first opening degree is greater than the second opening degree. This scheme allows the seawater flow rate used to dilute the concentrated brine salinity to be adjusted according to the concentrated brine salinity. When the concentrated brine salinity is high, the seawater flow rate is increased to fully dilute the concentrated brine salinity; when the concentrated brine salinity is low, the seawater flow rate is decreased to maintain the concentrated brine temperature.

[0063] In other embodiments, the hydro-thermal co-production unit 5 may further include a seawater pretreatment unit, which includes a quartz sand filter, a security filter and a scale inhibitor addition device connected in series. The inlet of the seawater pretreatment unit is an ambient temperature seawater input terminal, and the outlet of the seawater pretreatment unit is connected to the seawater inlet 7 of the hydro-thermal co-production unit 5.

[0064] Quartz sand filters primarily remove large particulate impurities such as suspended solids, silt, rust, and algae from water to reduce turbidity. They are often used as the first stage of physical filtration to protect downstream equipment.

[0065] Security filters are used for precision filtration. They can intercept tiny particles (such as fine sand, broken resin, etc.) that remain after quartz sand filtration, preventing them from entering subsequent equipment and avoiding scratches, blockages, or performance degradation.

[0066] The scale inhibitor addition device automatically, continuously, and precisely adds scale inhibitors (such as organophosphonic acids and their salts, polycarboxylic acid polymers, polyepoxysuccinic acid, etc.) to the return water to inhibit the scaling of inorganic salts such as calcium sulfate (CaSO4), calcium carbonate (CaCO3), barium sulfate (BaSO4), and strontium sulfate (SrSO4) on the surface, thereby stabilizing the system's water production and quality, and extending the equipment cleaning cycle and service life.

[0067] The seawater pretreatment unit can purify the seawater before it enters the hydrothermal co-generation unit 5, thereby reducing the adverse effects of impurities on the hydrothermal co-generation unit 5, such as blockage and corrosion.

[0068] In other embodiments, such as Figure 4 As shown, the hydro-thermal co-production unit 5 may further include a seawater preheating unit 21. The hot side inlet of the seawater preheating unit 21 is connected to the outlet pipe of the generator 10. The cold side inlet of the seawater preheating unit 21 is the input end of ambient temperature seawater. The cold side outlet of the seawater preheating unit 21 is connected to the seawater inlet 7 of the hydro-thermal co-production unit 5.

[0069] Through the seawater preheating unit 21, this application can use the high-temperature condensate discharged from the outlet pipe of the generator 10 to heat the ambient temperature seawater, thereby increasing the seawater temperature at the seawater inlet 7 entering the hydrothermal co-production unit 5 and thus increasing the freshwater production.

[0070] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For apparatus embodiments, since they are basically similar to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0071] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0072] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0073] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A hydrothermal co-production system, characterized in that, include: Steam turbine (2), hydrothermal co-production unit (5), absorption heat pump (9) and flash tank (16), wherein the absorption heat pump (9) includes generator (10), first evaporator (11), absorber (12) and condenser (13). The inlet of the steam turbine (2) is connected to the high-pressure steam pipeline (1), and the outlet of the steam turbine (2) is connected to the first extraction steam pipeline (3) and the second extraction steam pipeline (4). The high-temperature heat source inlet of the hydro-thermal co-production unit (5) is connected to the first extraction steam pipeline (3). The concentrated brine discharge pipeline (8) of the hydro-thermal co-production unit (5) is connected to the inlet of the flash tank (16). The steam outlet (17) of the flash tank (16) is connected to the inlet of the first evaporator (11). The outlet of the first evaporator (11) is connected to the inlet of the condenser (18) within the hydro-thermal co-production unit (5) through a pipeline. The absorber (12) is provided with a fluid inlet (14) to be heated, and the condenser (13) is provided with a fluid outlet (15) to be heated. The absorber (12) and the condenser (13) are connected by a pipe so that the fluid to be heated flowing out of the absorber (12) flows into the condenser (13) and flows out from the fluid outlet (15); The second extraction steam line (4) is connected to the inlet of the generator (10).

2. The hydrothermal co-production system according to claim 1, characterized in that, The freshwater discharge pipeline (6) of the hydrothermal co-production unit (5) is connected to the inlet (14) of the fluid to be heated.

3. The hydrothermal co-production system according to claim 2, characterized in that, A first three-way valve is provided on the freshwater discharge pipeline (6), and a second three-way valve is provided on the inlet (14) of the fluid to be heated. The first three-way valve and the second three-way valve are connected by a freshwater delivery pipeline.

4. The hydrothermal co-production system according to claim 1, characterized in that, The hydrothermal co-production unit (5) is a multi-effect distillation unit. The hydrothermal co-production unit (5) includes multiple evaporators and condensers connected in series. The condenser (18) connected to the outlet of the first evaporator (11) is the last stage of the multi-effect distillation unit.

5. The hydrothermal co-production system according to claim 1, characterized in that, The flash tank (16) includes at least three flash units connected in series. The pressure of each flash unit decreases progressively. The inlet of the first flash unit is connected to the concentrated brine discharge pipeline (8), and the concentrated brine outlet of the last flash unit is connected to the concentrated brine recovery pipeline. The steam outlets of each flash unit are connected to the inlet of the first evaporator (11) through a collection pipeline. A steam purification device is installed on the collection pipeline. The steam purification device is used to remove salt mist and impurities from the steam to prevent corrosion of the heat exchange tubes inside the first evaporator (11).

6. The hydrothermal co-production system according to claim 5, characterized in that, It also includes a preheating heat exchanger, and the flash tank (16) also has a seawater inlet for inputting seawater. The concentrated brine outlet of the final flash unit is connected to the hot side inlet of the preheating heat exchanger. The cold side inlet of the preheating heat exchanger is used to input seawater at ambient temperature. The cold side outlet of the preheating heat exchanger is connected to the seawater inlet.

7. The hydrothermal co-production system according to claim 6, characterized in that, A salinity detection device is installed on the concentrated brine recovery pipeline, and a flow regulating valve is installed at the seawater inlet. When the salinity of the concentrated brine detected by the salinity detection device exceeds a preset threshold, the opening degree of the flow regulating valve is the first opening degree. When the salinity of the concentrated brine detected by the salinity detection device does not exceed the preset threshold, the opening degree of the flow regulating valve is the second opening degree; The first opening is greater than the second opening.

8. The hydrothermal co-production system according to claim 1, characterized in that, The hydro-thermal co-production unit (5) also includes a seawater pretreatment unit, which includes a quartz sand filter, a security filter and a scale inhibitor addition device connected in series. The inlet of the seawater pretreatment unit is the ambient temperature seawater input end, and the outlet of the seawater pretreatment unit is connected to the seawater inlet (7) of the hydro-thermal co-production unit (5).

9. The hydrothermal co-production system according to claim 1, characterized in that, The hydro-thermal co-production unit (5) also includes a seawater preheating unit. The hot side inlet of the seawater preheating unit is connected to the outlet pipe of the generator (10). The cold side inlet of the seawater preheating unit is the input end of the ambient temperature seawater. The cold side outlet of the seawater preheating unit is connected to the seawater inlet (7) of the hydro-thermal co-production unit (5).

10. The hydrothermal co-production system according to claim 1, characterized in that, The hydrothermal co-production unit (5) is a multi-effect distillation unit. The hydrothermal co-production unit (5) includes multiple evaporators and condensers connected in series. The condenser (18) connected to the outlet of the first evaporator (11) is the penultimate stage of the multi-effect distillation unit.

Images