Novel push-pull type membrane distillation assembly for real-time visual monitoring of membrane pollution

Abstract

The invention relates to the technical field of membrane distillation, and discloses a novel push-pull type membrane distillation assembly for real-time visual monitoring of membrane pollution. The assembly comprises a shell, two photovoltaic units, two membrane distillation units, two refrigeration units and two visual units. The photovoltaic unit can convert solar energy into heat energy and electric energy and provide a heat source for membrane distillation; the refrigeration unit adopts a semiconductor refrigeration layer to cool the cold side; the visual unit comprises symmetrically arranged miniature waterproof cameras and is used for monitoring the membrane surface pollution state in real time; and the membrane distillation unit adopts a pull-out structure, so that the membrane distillation unit is convenient to quickly replace and maintain after being polluted. The device integrates photoelectric heat cogeneration, semiconductor refrigeration, waste heat recovery and visual monitoring, has the advantages of compact structure, low energy consumption, pollution visualization and convenience in maintenance, and is suitable for efficient and energy-saving membrane distillation operation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of membrane distillation, and particularly relates to a thermoelectric refrigeration air gap type membrane distillation assembly with two photovoltaic units, capable of utilizing light energy and provided with two visual units, and having a structure of a pull-out type. BACKGROUND

[0002] Environmental protection has become one of the core tasks of the national strategy, and efficient conversion and clean utilization of waste is an important link to achieve the double carbon goal. Industrial technology is constantly iterating and upgrading, and the generated waste liquid and solid waste show new characteristics, including an increase in pollutant types, complex characteristics, and an increase in processing difficulty. Among them, the organic pollutants in the waste liquid usually have high biological toxicity and are difficult to degrade, which can cause more significant harm and persistence if discharged into the environment. In addition, in actual engineering applications, traditional waste liquid treatment technologies often face problems such as low removal rate or high treatment cost. Therefore, it is urgent to develop a new type of efficient and economical treatment technology.

[0003] Membrane distillation technology has attracted widespread attention in recent years due to its excellent separation performance and significant energy-saving potential. As an innovative separation method combining thermodynamic distillation process and membrane separation technology, membrane distillation has been successfully applied in seawater desalination, brackish water treatment, and industrial wastewater concentration and desalination processes. This technology separates two solutions by a microporous hydrophobic membrane, uses the vapor pressure difference caused by the temperature difference on both sides as the driving force, and makes the volatile components in the high-temperature feed liquid pass through the hydrophobic membrane in gaseous form, while the liquid, insoluble substances and ions are effectively retained on the feed liquid side, thereby realizing the separation of volatile components and the concentration of the feed liquid.

[0004] Membrane distillation technology mainly includes four forms: direct contact, air gap, vacuum and gas sweeping. Among them, direct contact membrane distillation is the most widely studied form due to its simple structure, convenient operation and large membrane flux, but it has a large transmembrane heat conduction loss. Although air gap membrane distillation is relatively less studied, it is of great concern because it has the highest thermal efficiency among the four basic forms.

[0005] Current membrane distillation assemblies usually rely on cold water circulation to achieve cooling function on the cold side. Specifically, a refrigeration machine is needed to reduce the temperature of the cooling water to below 10℃, and the cooling water is transported to the cold side cavity of the membrane assembly through a pipeline. The cooling water circulates in the cavity to complete the cooling process. However, this cooling method has obvious shortcomings, including low cooling efficiency, significant cooling loss during cooling water circulation, and high energy consumption of refrigeration equipment.

[0006] The pollutants of the liquid material may deposit, adsorb or block on the membrane surface or in the membrane pores, and the current membrane distillation assembly lacks real-time monitoring of membrane pollution. SUMMARY

[0007] The present application provides a new membrane distillation assembly for real-time visual monitoring of membrane fouling by pulling, aiming at the deficiencies of the existing membrane distillation technology mentioned above.

[0008] The present application provides a new membrane distillation assembly for real-time visual monitoring of membrane fouling by pulling, which comprises a shell, two photovoltaic units, two membrane distillation units, two refrigeration units and two visual units, wherein the two membrane distillation units can realize complete membrane distillation process.

[0009] The shell of the membrane distillation assembly is composed of a cylinder, and the photovoltaic units and membrane distillation units are nested in the form of a circular cake inside the shell, which facilitates the fixation of the assembly.

[0010] In order to make the membrane distillation process proceed smoothly, a hot side cavity for the flow of hot feed liquid, a hydrophobic membrane and a cold side cavity are required.

[0011] Membrane distillation relies on temperature difference. In the upper distillation assembly, the hot side cavity is formed by the photovoltaic unit, which absorbs sunlight, raises the temperature of the liquid material, forms a high vapor pressure on the hot side surface of the hydrophobic membrane, and provides driving force for membrane distillation.

[0012] For photovoltaic units, including a substrate and a novel asymmetric self-assembled monolayer (HTL201) coated on the surface thereof, composed of a carbazole core and anchoring groups and spacer groups on both sides, used as a hole selection layer in a perovskite / silicon tandem solar cell. The shell is used as a transparent material, and HTL201 can convert solar heat into electrical energy, and then convert electrical energy into heat energy to provide heat for membrane distillation.

[0013] The shell is provided with a waste heat utilization water inlet and a waste heat utilization water outlet. The reacted liquid material is discharged through the sewage outlet, and the sewage outlet is connected to the waste heat utilization water inlet through an external pipeline. The liquid material is passed through the waste heat utilization pipeline to realize waste heat utilization and convert heat into useful energy inside the assembly.

[0014] The membrane distillation unit adopts a pull-out design. A handle is provided outside a piece of hydrophobic membrane and a piece of porous gasket arranged above the hydrophobic membrane. When the visual unit detects that the membrane pollution reaches a threshold value, the membrane is directly pulled out from the side of the shell through the handle for real-time replacement. The two are fixed and positioned by a circular strip-shaped flange arranged inside the shell to prevent falling off.

[0015] The visual unit is composed of two miniature waterproof cameras. The two cameras are embedded inside the shell, and their lenses are directly aimed at the membrane surface of the membrane distillation unit to directly obtain high-definition image data of the membrane hole wetting or dirt deposition in the membrane distillation process, so as to judge the membrane pollution condition and decide whether to perform manual pull-out and replacement of the membrane unit to maintain the working state of the membrane surface.

[0016] Compared with the traditional structure of directly cooling the cold side with cooling water, the semiconductor refrigeration layer structure has the advantages of high refrigeration efficiency, wide cooling range and low energy consumption. The traditional device not only takes a long time to cool down, but also has a limited cooling range. Especially when the hot side temperature is high, the cold side temperature is easily disturbed and difficult to reduce to the required low temperature. In addition, the traditional method requires very strict cooling water temperature, often relying on high-energy refrigeration to prepare low-temperature cooling water to operate. In the present application, the cold water is only used to provide auxiliary heat dissipation for the semiconductor refrigeration layer, and does not directly participate in the membrane distillation process, so the water temperature requirement is greatly reduced, and there is no need to pre-cool, which fundamentally reduces the system energy consumption.

[0017] The application integrates multiple innovative designs, which fundamentally improves the efficiency and maintainability of the membrane distillation process. Firstly, the photovoltaic unit is innovatively adopted. The device not only utilizes the high-efficiency power generation of the perovskite / silicon stacked cell, but also converts the unused solar energy into heat energy through its unique heat-absorbing substrate, directly providing a heat source for membrane distillation, realizing the efficient utilization of the three combined production of light, electricity and heat. Furthermore, the visual unit is introduced. Through the symmetrically embedded waterproof miniature camera in the shell, real-time visual monitoring of the membrane surface pollution condition is realized, providing a direct basis for system maintenance, and transforming the traditional passive maintenance relying on experience into active management based on real-time images. Secondly, the overall symmetrical integrated structure layout integrates photovoltaic, refrigeration, membrane distillation and visual unit compactly in one symmetrical shell, forming a collaborative system integrating energy utilization and monitoring, with compact structure and high functional integration. Finally, the pull-out membrane distillation unit is designed, which integrates the hydrophobic membrane and the porous gasket into a module that can be pulled out as a whole, and realizes quick replacement or cleaning through the handle structure, greatly reducing the downtime and maintenance cost caused by membrane pollution. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a whole structure cross-sectional view;

[0019] Figure 2 is a whole structure schematic diagram;

[0020] Figure 3 is an upper side distillation component arrangement cross-sectional view;

[0021] Figure 4 is a visual unit local enlarged schematic diagram;

[0022] shown in the figure: 1. shell, 1-1. upper side water inlet slot, 1-2. waste heat utilization water outlet slot, 1-3. lower side water inlet slot, 1-4. upper side sewage water outlet slot, 1-5. waste heat utilization water inlet slot, 1-6. lower side sewage water outlet slot, 1-7. upper side water outlet slot, 1-8. lower side water outlet slot, 2. upper side membrane distillation unit, 2-1. porous gasket, 2-2. hydrophobic membrane, 2-3. handle, 3. upper side photovoltaic unit, 4. top refrigeration unit, 5. upper side visual unit, 5-1. miniature waterproof camera one, 5-2. miniature waterproof camera two, 6. lower side photovoltaic unit, 7. lower side membrane distillation unit, 8. bottom refrigeration unit, 9. lower side visual unit. DETAILED DESCRIPTION

[0023] To more clearly illustrate the advantages of the technical solution of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Since the present invention adopts a symmetrical structure, the upper membrane distillation assembly and the lower membrane distillation assembly are completely identical in terms of components and component arrangement. Therefore, in the embodiments, the upper distillation assembly will be specifically described with reference to the accompanying drawings.

[0024] Example:

[0025] This invention provides a novel membrane distillation assembly for real-time visual monitoring of membrane fouling using a pull-out design. The assembly is characterized by having upper and lower hot-side chambers and two cold-side chambers. For example... Figure 1 As shown, the upper photovoltaic unit 2 and the upper membrane distillation unit 3 work together to achieve a complete membrane distillation process; similarly, the lower photovoltaic unit 6 and the lower membrane distillation unit 7 work together to achieve a complete membrane distillation process. Furthermore, the cold sides of the upper and lower distillation units of this module employ a semiconductor cooling layer.

[0026] like Figure 3 As shown, the upper interior of the housing 1 features precision-machined annular protrusions that nest tightly with the disc-shaped external structures of the upper photovoltaic unit 3 and the upper membrane distillation unit 2. Correspondingly, the lower side of the housing, following a standardized design, has protrusions of the same specifications as the upper side, facilitating the nesting of the lower photovoltaic unit and the lower membrane distillation unit. This adaptability design ensures accurate positioning and stable connection of each functional unit during assembly, not only facilitating the installation and disassembly of the photovoltaic unit and the membrane distillation unit but also effectively enhancing the system's sealing and structural integrity.

[0027] The upper visual unit 5 and the lower visual unit 9 of this invention are each composed of two miniature waterproof cameras. Figure 4 As shown, the miniature waterproof camera 5-1 and miniature waterproof camera 5-2 inside the upper vision unit 5 are symmetrically embedded in the preset mounting positions on the upper side of the housing, precisely aligned with the hydrophobic membrane surface in the membrane distillation unit. During system operation, the cameras continuously acquire real-time high-definition images of the membrane surface area, clearly showing the state of membrane pore wetting, crystallization, or contaminant adhesion. Based on the above image information, the degree and trend of membrane fouling can be judged, thereby making timely decisions on whether to remove and replace the membrane module. This vision unit provides a reliable basis for intuitive judgment and maintenance of the membrane state, significantly improving the orderliness of membrane management and system maintainability.

[0028] A handle 2-3 is provided on the outside of the upper membrane distillation unit 2. When the vision unit 5 located on the upper side of the device detects a high degree of fouling of the hydrophobic membrane 2-2, the entire membrane distillation unit can be smoothly pulled out for replacement or cleaning. A handle is also provided on the outside of the lower membrane distillation unit 7, which can also be smoothly pulled out. This pull-out structure significantly improves the convenience of membrane maintenance operations, allowing replacement to be completed without disassembling other parts, greatly reducing system downtime.

[0029] The upper photovoltaic unit 3 consists of a substrate and a novel asymmetric self-assembled monolayer coated on its surface. It can efficiently convert absorbed solar energy into electrical energy, and then into heat energy, which is then applied to the liquid in the hot-side cavity. In this process, heat is transferred from the upper photovoltaic unit 3 to the liquid by conduction. Due to the short conduction path and low thermal resistance, heat loss is greatly reduced, resulting in a significant improvement in energy utilization efficiency.

[0030] Semiconductor refrigeration, also known as electronic refrigeration or thermoelectric refrigeration, utilizes a PN junction formed by special semiconductor materials to create thermocouple pairs, thereby generating the Peltier effect and achieving heat transfer. It is a novel refrigeration method that directly cools using direct current. It features no mechanical movement and high refrigeration efficiency. In membrane distillation, the cold side requires a low temperature. This invention utilizes a semiconductor refrigeration layer to cool the cold side, replacing the traditional membrane distillation module's method of relying on a refrigeration mechanism to draw cold water, which continuously circulates within the cold-side cavity to lower the cold-side temperature.

[0031] This invention innovatively employs a semiconductor cooling layer to achieve cooling on the cold side, effectively overcoming the shortcomings of traditional methods. By precisely integrating the semiconductor cooling layer into the membrane distillation assembly, its unique cooling properties provide a stable and efficient cooling effect for the cold side, thereby ensuring that the membrane distillation process proceeds smoothly under a suitable temperature difference.

[0032] like Figure 3 As shown, the porous gasket 2-1 itself has a channel design that defines the flow path of the fluid, ensuring that hot water can flow evenly across the entire membrane surface, making full use of all effective membrane area and avoiding local membrane surface impact.

[0033] like Figure 1As shown, this invention achieves efficient energy recycling within the system through a waste heat recovery pipeline. Specifically, the high-temperature concentrate generated during the membrane distillation process is discharged from the upper wastewater outlet 1-4 and then transported via an external pipeline loop to the waste heat recovery inlet 1-5, re-entering the system. This high-temperature concentrate flows through the built-in waste heat exchange pipeline, transferring its waste heat to the newly entering feed liquid, thereby preheating the cold-side feed. This closed-loop design significantly reduces the energy load of the system's heating unit and achieves efficient in-situ recovery of waste heat resources.

[0034] To more clearly illustrate the structure of the membrane distillation assembly of the present invention, the following description is provided in conjunction with... Figure 1 and Figure 2 The working process of this membrane distillation unit is explained.

[0035] The working fluid to be treated enters the hot-side cavity through the upper water inlet 1-1. It absorbs heat from solar energy, converts it into electrical energy, and then uses that electrical energy to generate heat. The upper photovoltaic unit 3 heats the liquid before it enters the hydrophobic membrane 2-2. Simultaneously, the top cooling unit 4 continuously cools the cold-side cavity. When a certain temperature difference is reached between the hot and cold sides, some moisture in the hot-side cavity permeates through the hydrophobic membrane 2-2 as water vapor. The liquid passes through the hydrophobic membrane 2-2 and the porous gasket 2-1, forming a fixed flow channel. Wastewater is discharged from the upper wastewater outlet 1-4 into an external pipe. The treated liquid is collected as water vapor from the upper water outlet 1-7. Waste in the upper wastewater outlet 1-4 is connected to the waste heat utilization inlet 1-5 and passes through the internal pipes of the shell, while wastewater exits from the waste heat utilization outlet 1-2. During this process, the miniature waterproof cameras 5-1 and 5-2 in the upper vision unit 5 monitor the membrane surface to detect membrane fouling. The distillation process of the lower membrane distillation unit is exactly the same, so it will not be described in detail here.

Claims

1. A novel membrane distillation module for real-time visual monitoring of membrane fouling via a pull-out design, the membrane distillation module comprising a housing, two photovoltaic units, two membrane distillation units, two cooling units, and two vision units; characterized in that: The membrane distillation assembly is symmetrically distributed vertically; two photovoltaic units are symmetrically distributed on the upper and lower sides of the middle of the housing; two membrane distillation units are symmetrically arranged on the upper and lower sides inside the housing; two cooling units correspond to the top and bottom of the housing respectively; and two vision units are symmetrically installed on the upper and lower sides of the inner wall of the housing.

2. The membrane distillation assembly according to claim 1, characterized in that: The shell is equipped with a water inlet, a water outlet, a sewage outlet, a waste heat utilization water inlet, and a waste heat utilization water outlet.

3. The membrane distillation assembly according to claim 1, characterized in that: The cooling unit is composed of a convex circular semiconductor cooling layer.

4. The membrane distillation assembly according to claim 1, characterized in that: The membrane distillation unit includes a hydrophobic membrane and a porous gasket disposed above it; there is a sealing rubber strip between the hydrophobic membrane and the porous gasket and the contact surface with the housing; the hydrophobic membrane and the porous gasket are positioned and fixed by a circular strip flange disposed inside the housing; the hydrophobic membrane and the porous gasket are provided with handles on the outside for easy pulling and replacement.

5. The membrane distillation assembly according to claim 1, characterized in that: The photovoltaic unit includes a substrate and a novel asymmetric self-assembled monolayer (HTL201) coated on its surface. The HTL201 is composed of a carbazole core and anchoring groups and spacer groups on both sides. It is used as a hole selection layer in a perovskite / silicon tandem solar cell to convert light energy into electrical energy and then into heat energy.

6. The membrane distillation assembly according to claim 1, characterized in that: The vision unit consists of two miniature waterproof cameras, which are symmetrically embedded in the inner wall of the housing and face the surface of the membrane distillation unit for real-time monitoring of membrane fouling.

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