A porous material thermal distillation water purification system driven by working fluid circulation

Abstract

The present invention belongs to the technical field of water treatment, and relates to a porous material thermal distillation water purification system based on working medium circulation drive. The system mainly includes a Carnot cycle device, a porous material, and a closed cavity. The Carnot cycle device is composed of a compressor, a condensation heat release plate, an expansion valve, and an evaporative refrigeration plate. The porous material, the condensation heat release plate, and the evaporative refrigeration plate are placed in a closed cavity. The system can simultaneously realize the thermal distillation concentration of wastewater and the production of clean water. When the system is working, the wastewater to be treated is guided to the porous material, and the porous material absorbs the wastewater and evaporates it. At the same time, the condensation heat release end of the Carnot cycle device heats the porous material after absorbing water to enhance the evaporation effect, and the evaporative refrigeration plate of the Carnot cycle device serves as a low-temperature condensation end to enhance the condensation reflux effect of water vapor. The system is of great significance for compact and efficient clean water production applications, and is easy to use for large-scale parallel factory clean water treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment and relates to a porous material thermal distillation water purification system based on working medium circulation drive. Background Art

[0002] At present, the world is facing a severe challenge of insufficient clean water resources. Research and analysis show that by 2050, at least half of the world's population will face a shortage of fresh water resources. Existing clean water production technologies include reverse osmosis, electrodialysis, thermal distillation, etc., and there is still a contradiction between high efficiency, yield, energy consumption ratio and floor space. Specifically, thermal distillation technology, including specific technical principles such as multi-effect distillation, multi-stage flash evaporation, membrane distillation, and solar thermal distillation, also faces the problem of inflexibility of high-efficiency equipment and inefficiency of flexible equipment.

[0003] Porous materials have excellent properties such as low density and high specific surface area. Using porous materials to adsorb wastewater for evaporation has a very fast effect. However, obtaining clean water through a single evaporation and condensation process is an energy-consuming process, and the condensation heat needs to be effectively recovered. By introducing the hot and cold temperature difference driven by the working fluid cycle, heat energy can be directly provided to the evaporation process in the thermal distillation and heat energy can be absorbed by the condensation process, resulting in efficient energy recycling. Summary of the invention

[0004] The purpose of the present invention is to propose a porous material thermal distillation water purification system driven by working fluid circulation. By utilizing the characteristics of porous materials and introducing the hot and cold temperature difference driven by working fluid circulation, heat energy is directly provided to the evaporation process in the thermal distillation and heat energy is absorbed by the condensation process, thereby generating efficient energy recycling.

[0005] The porous material thermal distillation water purification system driven by working fluid circulation proposed in the present invention comprises a porous material, a condensation heat release plate, an evaporation refrigeration plate, a closed cavity, an expansion valve and a compressor; the porous material, the condensation heat release plate and the evaporation refrigeration plate are placed in the closed cavity, and the porous material and the condensation heat release plate are in contact with each other; the compressor, the condensation heat release plate, the expansion valve and the evaporation refrigeration plate are connected head to tail in sequence to form a closed Carnot cycle loop.

[0006] In the above-mentioned porous material thermal distillation water purification system, the porous material and the condensation heat release plate are bonded back to back, or the porous material is coated on the outside of the condensation heat release plate.

[0007] In the porous material thermal distillation water purification system, the method for preparing the porous material comprises the following steps:

[0008] (1) dissolving a functional material in water to obtain an aqueous solution of the functional material, wherein the mass percentage concentration of the functional material is 0.01% to 10%, and the functional material is graphene oxide, carbon nanotubes or polyvinyl alcohol;

[0009] (2) placing the functional material aqueous solution in a low temperature cold trap and freezing it into ice crystal blocks;

[0010] (3) placing the ice crystal block in a low-temperature vacuum dryer for freeze-drying treatment, wherein the freeze-drying temperature is -100 to -10°C, the vacuum pressure is 0.1 to 20 Pa, and the drying time is 0.5 to 10 days to obtain a porous material constructed with functional materials.

[0011] In the porous material thermal distillation water purification system, the porosity of the porous material is 10-99%, and the average pore size of the porous material is 10 nanometers to 10 centimeters.

[0012] The porous material thermal distillation water purification system driven by working medium circulation proposed in the present invention has the following advantages:

[0013] 1. In the porous material thermal distillation water purification system driven by working fluid circulation of the present invention, porous materials are used for heat absorption and water absorption evaporation, and have efficient evaporation heat and mass transfer performance; combined with a Carnot cycle device, efficient recovery of energy in the evaporation and condensation process of the porous material is ensured; wherein the single-machine Carnot cycle combined with porous material thermal distillation has a wastewater desalination technology with large flux and high energy efficiency ratio in a compact and small space; the porous material is not easy to scale and clog during the infiltration and evaporation process, can work for a long time, and is applied to the desalination and concentration treatment of various wastewaters.

[0014] 2. The porous material thermal distillation water purification system driven by working medium circulation of the present invention has excellent clean water production rate, high energy efficiency ratio, and compact system footprint. It can desalinate and concentrate wastewater in a compact and efficient manner for a long time.

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, and can be implemented according to the contents of the description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of the porous material thermal distillation water purification system driven by working fluid circulation proposed in the present invention.

[0017] Figure 2 This is an application status diagram of the porous material thermal distillation water purification system of the present invention.

[0018] Figure 1 and Figure 2 In the figure, 1 is a porous material, 2 is a condensation heat release plate, 3 is an evaporation refrigeration plate, 4 is a closed cavity, 5 is an expansion valve, 6 is a compressor, 7 is a wastewater storage tank, 8 is a clean water storage tank, 9 is a wastewater circulation water supply pump, 10 is a wastewater circulation reflux pump, and 11 is a clean water collection pump. DETAILED DESCRIPTION

[0019] The porous material thermal distillation water purification system driven by working medium circulation proposed by the present invention has a structure as follows Figure 1 As shown, it includes a porous material 1, a condensation heat release sheet 2, an evaporation refrigeration sheet 3, a closed cavity 4, an expansion valve 5 and a compressor 6; the porous material 1, the condensation heat release sheet 2 and the evaporation refrigeration sheet 3 are placed in the closed cavity 4, and the porous material 1 and the condensation heat release sheet 2 are attached to each other; the compressor 6, the condensation heat release sheet 2, the expansion valve 5 and the evaporation refrigeration sheet 3 are connected head to tail in sequence to form a closed Carnot cycle loop.

[0020] In the above-mentioned porous material thermal distillation water purification system, the porous material and the condensation heat release plate are bonded back to back, or the porous material is coated on the outside of the condensation heat release plate.

[0021] In the porous material thermal distillation water purification system, the method for preparing the porous material comprises the following steps:

[0022] (1) dissolving a functional material in water to obtain an aqueous solution of the functional material, wherein the mass percentage concentration of the functional material is 0.01% to 10%, and the functional material is graphene oxide, carbon nanotubes or polyvinyl alcohol;

[0023] (2) placing the functional material aqueous solution in a low temperature cold trap and freezing it into ice crystal blocks;

[0024] (3) placing the ice crystal block in a low-temperature vacuum dryer for freeze-drying treatment, wherein the freeze-drying temperature is -100 to -10°C, the vacuum pressure is 0.1 to 20 Pa, and the drying time is 0.5 to 10 days to obtain a porous material constructed with functional materials.

[0025] The porous material in the porous material thermal distillation water purification system has a porosity of 10 to 99%, and an average pore size of 10 nanometers to 10 centimeters.

[0026] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.

[0027] In one application embodiment of the present invention, the structure of the porous material thermal distillation water purification system is as follows: Figure 2As shown, it is composed of porous material 1, condensation heat release sheet 2, evaporation refrigeration sheet 3; closed cavity 4, expansion valve 5, compressor 6, wastewater storage tank 7, clean water storage tank 8, wastewater circulation water supply pump 9, wastewater circulation reflux pump 10, and clean water collection pump 11. The compressor 6, condensation heat release sheet 2, expansion valve 5 and evaporation refrigeration sheet 3 are connected head to tail into a closed loop to form the Carnot cycle device. The porous material 1, condensation heat release sheet 2 and evaporation refrigeration sheet 3 are placed in the closed cavity 4, and the porous material 1 fits the condensation heat release sheet 2. The wastewater storage tank 7 connects the wastewater inlet, the concentration outlet, the wastewater circulation water supply pump 9 and the wastewater circulation reflux pump 10. The pipeline of the wastewater circulation water supply pump 9 is opened above the closed cavity 4 and contacts the upper end of the porous material 1. The pipeline of the wastewater circulation reflux pump 10 is opened below the closed cavity 4. The clean water storage tank 8 is connected to the clean water outlet and the clean water collecting pump 11 .

[0028] When the system is working, wastewater is introduced into the wastewater storage tank 7 from the wastewater inlet, and the wastewater circulation water supply pump 9 pumps wastewater from the wastewater storage tank 7 to the upper end of the porous material 1. The porous material 1 spontaneously absorbs wastewater and evaporates clean water vapor. The evaporated concentrated wastewater flows from the lower end of the porous material 1 to the wastewater circulation reflux pump 10 and is pumped back to the wastewater storage tank 7. The clean water vapor evaporated from the porous material 1 condenses into clean water droplets on the evaporative cooling plate 3 and drips back to the clean water collection pump 11. The clean water collection pump 11 pumps the clean water into the clean water storage tank 8. The clean water in the clean water storage tank 8 can be transmitted to the lower level through the clean water outlet for drinking, irrigation and other purposes. The role of the Carnot cycle device is to enhance the heat supply in the evaporation process of water and the heat extraction in the condensation process. Specifically, the compressor 6 is powered on to work, driving the internal working fluid gas to be compressed into a high-temperature and high-pressure state, and the working fluid gas flows into the condensation heat release plate 2, condenses in the internal pipe of the condensation heat release plate 2 and releases a large amount of heat. The heat released from the outside heats the porous material 1 in contact with it, thereby enhancing the evaporation of the porous material 1; at the same time, the low-temperature and high-pressure working fluid liquid after condensation and heat release flows through the expansion valve, converted into a low-temperature and low-pressure liquid state, and evaporates into gas inside the evaporative refrigeration plate 3 and absorbs a large amount of heat. The heat absorbed from the outside is manifested as the heat released by the condensed water droplets, thereby maintaining a low-temperature and efficient condensation water capability on the surface of the evaporative refrigeration plate 3.

[0029] The porous material used in the system of the present invention and the functional material used in the preparation process can be selected from graphene oxide, carbon nanotubes or polyvinyl alcohol, etc.; the process for preparing the porous structure can be freeze drying, thermal foaming, etching and 3D printing, etc.

[0030] In an embodiment of the present invention, when graphene oxide is used as a functional material for preparing a porous material, the mass percentage concentration of graphene oxide is 1.5%, the total amount of the solution is 100 g, the temperature during freeze-drying is -47°C, the vacuum pressure is 10 Pa, the drying time is 3 days, and the porosity of the obtained porous material is 99%, and the average pore size of the porous material is 100 microns.

[0031] In an embodiment of the present invention, when carbon nanotubes are used as functional materials for preparing porous materials, the mass percentage concentration of the carbon nanotubes is 0.5%, the total amount of the solution is 50 g, the temperature during freeze-drying treatment is -55°C, the vacuum pressure is 6 Pa, the drying time is 2 days, and the porosity of the obtained porous material is 99.3%, and the average pore size of the porous material is 30 microns.

[0032] In an embodiment of the present invention, when polyvinyl alcohol is used as a functional material for preparing a porous material, the mass percentage concentration of polyvinyl alcohol is 5%, the total amount of the solution is 200 g, the temperature during freeze-drying treatment is -45°C, the vacuum pressure is 15 Pa, the drying time is 5 days, and the porosity of the obtained porous material is 91%, and the average pore size of the porous material is 300 microns.

[0033] In the embodiment of the present invention, the compressed working fluid inside the Carnot cycle device can be selected according to the requirements of power, environmental protection and safety. R404A (pentafluoroethane / trifluoroethane / tetrafluoroethane mixture), R410A (difluoromethane / pentafluoroethane mixture), R134a (tetrafluoroethane), etc. can be used. The refrigerant supply company can be selected from DuPont, Honeywell, Zhejiang Juhua, etc. (the model of the refrigerant is its abbreviation, such as R134a). The selection of the compressor in the Carnot cycle device should be matched according to the designed condensing power of the system and selected from commercially available compressors. The selection of the condensing heat sink and the evaporative refrigeration fin in the Carnot cycle device should be based on the designed power of the compressor. For example, for a compressor with a cooling capacity of 500W, a condensing heat sink and an evaporative heat sink with a nominal heat dissipation power equal to or slightly greater than 500W should be selected. The same model can be selected for both, such as the CP26240 model of Pailang Technology Co., Ltd. The preparation process of the closed cavity is mainly determined by the material selection and can be selected according to the general principles of the industry.

[0034] In the porous material thermal distillation water purification system of the present invention, water vapor cannot escape into the atmosphere during the evaporation and condensation process, so the closed cavity included in the system and the connections between other components and pipelines need to be sealed.

[0035] In the porous material thermal distillation water purification system driven by working fluid circulation of the present invention, the lamination of the porous material 1 and the condensation heat release sheet 2 can be in surface contact between the porous material 1 and the condensation heat release sheet 2, or in physical contact mode in which the porous material 1 entirely covers the condensation heat release sheet 2. The entire covering process is that the porous material 1 is directly prepared and formed on the surface of the condensation heat release sheet 2. For example, in order to prepare the porous material 1 by freeze drying, the functional material aqueous solution is first immersed in the condensation heat release sheet 2 or coated on the surface of the condensation heat release sheet 2, and then the condensation heat release sheet 2 with the functional material aqueous solution attached to the surface is placed in a low-temperature freeze dryer, and freeze dried for a suitable time, so that the condensation heat release sheet 2 entirely covered with the porous material 1 can be obtained.

Claims

1. A porous material thermal distillation water purification system driven by working fluid circulation, characterized in that: The porous material thermal distillation water purification system comprises a porous material, a condensation heat release sheet, an evaporation refrigeration sheet, a closed cavity, an expansion valve and a compressor; the porous material, the condensation heat release sheet and the evaporation refrigeration sheet are placed in the closed cavity, and the porous material and the condensation heat release sheet are attached to each other; the compressor, the condensation heat release sheet, the expansion valve and the evaporation refrigeration sheet are connected head to tail in sequence to form a closed Carnot cycle loop; The method for preparing the porous material comprises the following steps: (1) dissolving a functional material in water to obtain an aqueous solution of the functional material, wherein the mass percentage concentration of the functional material is 0.01 to 10%, and the functional material is graphene oxide, carbon nanotubes or polyvinyl alcohol; (2) placing the functional material aqueous solution in a low-temperature cold trap and freezing it into ice crystal blocks; (3) Place the ice crystal block in a low-temperature vacuum dryer for freeze-drying at a temperature of -100 to -10 o C, the vacuum pressure is 0.1-20 Pa, the drying time is 0.5-10 d, and a porous material constructed with functional materials is obtained.

2. The porous material thermal distillation water purification system according to claim 1, characterized in that: The porous material and the condensation heat release plate are bonded back to back, or the porous material is coated on the outside of the condensation heat release plate.

3. The porous material thermal distillation water purification system according to claim 1, characterized in that: The porosity of the porous material is 10-99%, and the average pore size of the porous material is 10 nanometers to 10 centimeters.

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