Visual experiment system based on nanometer steam condensation

Abstract

The invention provides a visual experiment system based on nanometer steam condensation, and belongs to the technical field of condensation heat exchange, the visual experiment system comprises a steam circulation module, a water circulation module, an experiment cavity, a vacuum pump and a condensation pipe, the condensation pipe is installed in the experiment cavity, the condensation pipe is connected with the water circulation module, and the vacuum pump is connected with the condensation pipe. The steam circulation module comprises a steam generator and a nano-particle blender, water is contained in the steam generator, nano-particles are contained in the nano-particle blender, and the steam circulation module is used for mixing steam generated by the steam generator with the nano-particles and then introducing the mixture into the experiment cavity; compared with condensation phase-change heat transfer outside a pipe of a traditional working medium, the condensation mode of the steam containing the nano particles and the deposition condition of the nano particles on the condensation wall surface outside the pipe are researched, and the heat transfer performance of condensation phase-change heat transfer is improved according to the characteristics. Therefore, energy conservation and consumption reduction are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of condensation heat exchange, and in particular is a visualization experimental system based on nano steam condensation. Background Art

[0002] As energy shortages become increasingly prevalent worldwide, improving energy efficiency is crucial. Condensation-enhanced heat transfer is crucial in industrial applications and a key component in energy conservation and emission reduction. Condensation phase change technology enables systems to maintain stable operating conditions and achieve energy transfer and conduction, finding widespread application in low-temperature refrigeration, seawater desalination, and high-power cooling.

[0003] Nanofluids are novel heat transfer fluids characterized by uniformly dispersing metallic or non-metallic nanoparticles in traditional heat transfer media such as water, alcohols, and oils, resulting in high thermal conductivity, stability, and fluidity. As a new type of heat transfer fluid, nanofluids possess unique properties. The addition of nanoparticles can effectively improve the heat transfer performance of thermal systems, offering potential applications in a variety of fields. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the embodiments of the present invention is to provide a visualization experiment system based on nano-steam condensation.

[0005] To solve the above technical problems, the present invention provides the following technical solutions: a visualization experiment system based on nano-steam condensation, comprising a steam circulation module, a water circulation module, a data acquisition module, a control module, an experimental cavity, a vacuum pump, and a condenser. The condenser is installed in the experimental cavity, and the condenser is connected to the water circulation module. The water circulation module is used to circulate cooling water in the condenser. The vacuum pump is connected to the experimental cavity and is used to provide the pressure required for the experiment.

[0006] The steam circulation module includes a steam generator and a nanoparticle blender. The steam generator is filled with water, and the nanoparticle blender is filled with nanoparticles. The steam circulation module is used to mix the steam generated by the steam generator with the nanoparticles and then pass them into the experimental cavity. The steam circulation module is connected to the experimental cavity and circulates;

[0007] The data acquisition module is used to collect the pressure data in the experimental cavity, the water inlet and outlet temperature data, the steam temperature data, the condenser surface temperature data, the water flow rate and the condensation image of the experimental cavity;

[0008] The control module is connected to the data acquisition module, and the control module is used to control the pressure of the experimental cavity through the data acquisition module.

[0009] As a further improved scheme: the water circulation module comprises a circulating water pump and a constant temperature water tank, and the circulating water pump is connected with the constant temperature water tank.

[0010] As a further improved scheme: the gas supply pipeline, the exhaust pipeline and the water circulation pipeline are all provided with valves.

[0011] As a further improved scheme: the gas supply pipeline and the exhaust pipeline are both provided with electromagnetic valves, and the electromagnetic valves are controlled by a control module.

[0012] As a further improved scheme: the nanoparticle mixing device and the discharge pipeline of the steam generator are wrapped with heating elements.

[0013] As a further improved scheme: the experimental cavity is wrapped with a heating element, and the experimental cavity is provided with a heat preservation layer inside and outside.

[0014] As a further improved scheme: a clamping sleeve joint is arranged between the two ends of the condenser pipe and the water circulation pipeline.

[0015] Compared with the prior art, the beneficial effects of the present application are: the dry nanoparticles in the nanoparticle mixing device are impacted by high-pressure superheated steam to directly generate nano-steam, the concentration of the nano-steam is more accurate through the above-mentioned way, the concentration is directly calculated by the initial particle mass, the agglomeration and sedimentation problem during the premixing of the nano-fluid is avoided, higher concentration of nanoparticles can be entrained, and the upper limit of the concentration of the traditional nano-fluid is broken through. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The present application is a visualized experimental system based on nano-steam condensation.

[0017] Figure 2 The experimental cavity back connection diagram of the present application.

[0018] Figure 3 The system circulation diagram of the present application.

[0019] In the figure: 1. Steam generator; 2. Ceramic heating coil; 3. Air supply ball valve; 4. Nanoparticle blender; 5. Air supply solenoid valve; 6. Digital pressure switch; 7. Temperature measuring resistor; 8. Condenser; 9. Insulation layer; 10. Compression fitting; 11. First thermocouple; 12. Exhaust solenoid valve; 13. Exhaust ball valve; 14. Vacuum pump; 15. Circulating water pump; 16. Constant temperature water tank; 17. High-speed camera; 18. Glass flange sight glass; 19. Flow meter; 20. Cooling water ball valve; 21. Silicone heating coil; 22. Experimental chamber; 23. Second thermocouple; 24. Steam inlet; 25. Condensate inlet; 26. First thermal resistor connection port; 27. Digital pressure switch interface; 28. Second thermal resistor connection port; 29. ​​Condensate outlet; 30. Vacuum pump interface. DETAILED DESCRIPTION

[0020] The technical solution of the present application will be further described in detail below in conjunction with specific implementation methods.

[0021] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0022] See also Figure 1 、 Figure 2 、 Figure 3 In one embodiment, a visualization experiment system based on nano-steam condensation includes a steam circulation module, a water circulation module, a data acquisition module, a control module, an experimental chamber 22, a vacuum pump 14, and a condenser 8. The condenser 8 is installed in the experimental chamber 22, and the condenser 8 is connected to the water circulation module. The water circulation module is used to circulate cooling water in the condenser 8. The vacuum pump 14 is connected to the experimental chamber 22 and is used to provide the pressure required for the experiment.

[0023] The steam circulation module includes a steam generator 1 and a nanoparticle blender 4. The steam generator 1 is filled with water, and the nanoparticle blender 4 is filled with nanoparticles. The steam circulation module is used to mix the steam generated by the steam generator 1 with the nanoparticles and then pass them into the experimental cavity 22. The steam circulation module is connected to the experimental cavity 22 and circulates;

[0024] The data acquisition module is used to collect pressure data in the experimental cavity 22, water inlet and outlet temperature data, steam temperature data, condenser 8 surface temperature data, water flow rate and condensation image of the experimental cavity 22;

[0025] The control module is connected to the data acquisition module, and the control module is used to control the pressure of the experimental cavity 22 through the data acquisition module.

[0026] In this embodiment, deionized water is placed in the steam generator 1 in the steam circulation module, heated to generate high-pressure steam, which enters the experimental chamber 22 through the air supply pipeline and can be discharged through the exhaust pipeline after the experiment.

[0027] The data acquisition module includes a first thermocouple 11, a second thermocouple 23, two temperature measuring resistors 7, a flow meter 19, a high-speed camera 17, and a digital pressure switch 6, which respectively monitor the cooling water inlet and outlet temperatures, steam temperature, surface temperature of the condenser 8, water flow, condensation conditions in the cavity, and pressure in the experimental cavity 22, and monitor the temperature changes of the system in real time. The high-speed camera 17 uses a glass flange sight glass 18 to shoot the nano-steam condensation phenomenon in real time, directly observe and record the nano-particle deposition dynamics and condensation droplet behavior in real time, capture micro-scale phenomena that are difficult to observe in traditional experiments, such as the formation and shedding of liquid films and droplets, and achieve synchronization of temperature, pressure, flow and other data with image time, and realize the correlation analysis of condensation phenomena and heat transfer performance. The flow meter 19 adopts a turbine flow meter, and a turbine flow meter is arranged on the external cooling water pipeline to measure the cooling water flow in real time.

[0028] The digital pressure switch 6 is mounted on the experimental chamber 22. The flowmeter 19 is installed between the condenser 8 and the water circulation line of the constant temperature water tank 16. The high-speed camera 17 is mounted on one side of the experimental chamber 22. The front of the experimental chamber 22 is equipped with a glass flange sight glass 18 as an observation window. Through this window, the high-speed camera 17 captures and records steam condensation and particle deposition on the surface of the condenser 8. The experimental chamber 22 is made of a stainless steel quick-open sight glass manhole cover. The front of the chamber is sealed with a quick-open flange interface and an integrated tempered glass flange, which provides good light transmittance and facilitates visualization. The back of the chamber is welded to a steel plate to seal the chamber, and holes are opened in the steel plate to weld the required connection ports for the experiment. Thermocouples are inserted into the inlet and outlet pipes outside the experimental chamber 22 to measure the temperature of the cooling water inlet and outlet. Two temperature sensor interfaces are provided on the back of the chamber: two temperature measuring resistors 7 are inserted into the center of the chamber to measure the internal steam temperature and fixed to the wall of the condenser 8 to measure the wall temperature. The digital pressure switch measures the internal steam pressure of the chamber through these interfaces and displays the internal pressure.

[0029] The vacuum pump 14 draws air through the exhaust pipe to achieve a vacuum in the cavity, thereby ensuring a clean environment and eliminating interference from non-condensable gases as much as possible.

[0030] The back of the experimental chamber 22 is correspondingly provided with a steam inlet 24, a condensed water inlet 25, a first thermal resistor connection port 26, a digital pressure switch interface 27, a second thermal resistor connection port 28, a condensed water outlet 29 and a vacuum pump interface 30.

[0031] By installing a hollow cylindrical nanoparticle blender 4 in the steam pipeline, superheated steam impacts the nanoparticles placed in the blender to produce nanosteam. This experimental system allows for visualization of steam entrained with different nanoparticles and concentrations on single tubes and tube bundles of varying structures, sizes, and placement angles. This system can also study the condensation of nanofluids outside the tubes and the deposition of nanoparticles on the condensation tube 8 by varying conditions such as the working fluid, superheat, steam pressure, and nanoparticle concentration, further understanding the condensation of nanosteam outside the tubes.

[0032] The dry nanoparticles in the nanoparticle blender 4 are impacted by high-pressure superheated steam to directly generate nanosteam. The concentration of the nanosteam is more accurately controlled by the above method. The concentration is directly calculated based on the initial particle mass, avoiding the agglomeration and sedimentation problems during the premixing of the nanofluid. It can carry nanoparticles with a higher concentration, breaking the upper limit of the traditional nanofluid concentration.

[0033] See also Figure 1 、 Figure 2 In one embodiment, the water circulation module includes a circulating water pump 15 and a constant temperature water tank 16 , and the circulating water pump 15 is connected to the constant temperature water tank 16 .

[0034] In this embodiment, the cooling water is circulated in the cooling water system by a water pump, and the temperature of the cooling water is precisely controlled by the constant temperature water tank 16, which achieves precise temperature control of ±0.1°C.

[0035] See also Figure 1 、 Figure 2 In one embodiment, valves are installed on the gas supply pipeline, the exhaust pipeline and the water circulation pipeline.

[0036] In this embodiment, ball valves are provided in the air supply pipeline, the exhaust pipeline and the cooling water circuit to control the circuit switches, namely the air supply ball valve 3, the exhaust ball valve 13 and the cooling water ball valve 20.

[0037] See also Figure 1 、 Figure 2 In one embodiment, solenoid valves are installed on both the air supply pipeline and the exhaust pipeline, and the solenoid valves are controlled by a control module.

[0038] In this embodiment, a solenoid valve is provided on each of the gas supply pipeline and the exhaust pipeline. The solenoid valve includes a gas supply solenoid valve 5 and an exhaust solenoid valve 12, which are respectively installed on the gas supply pipeline and the exhaust pipeline. The solenoid valve switch is controlled by the output signal of the digital pressure switch 6. The steam flow is controlled by the solenoid valve with high control accuracy, and the pressure in the vacuum chamber can be kept constant.

[0039] See also Figure 1 、 Figure 2 In one embodiment, the nanoparticle blender 4 and the outer periphery of the discharge pipeline of the steam generator 1 are wrapped with a heating element.

[0040] In this embodiment, the heating element can be a ceramic heating ring 2. The outer periphery of the nanoparticle blender 4 and the discharge pipeline of the steam generator 1 are wrapped with the ceramic heating ring 2, and the air supply pipeline is also wrapped with the ceramic heating ring 2. The superheated steam is generated by the ceramic heating ring 2. The superheated steam passes through the nanoparticle blender 4, which is a hollow cylinder. The nanoparticle blender 4 is filled with nanoparticles, which are entrained by the superheated steam to generate nanometer steam. The concentration of the nanometer steam can be adjusted by the mass of the nanoparticles.

[0041] Please refer to Figure 1 、 Figure 2 In one embodiment, the experimental cavity 22 is wrapped with a heating element on the outside, and is provided with a heat preservation layer 9 on the inside and the outside.

[0042] In this embodiment, the air supply pipeline is also wrapped with a heat preservation material to reduce steam heat loss. The heating element can be a silica gel heating ring 21. The experimental cavity 22 is wrapped with the silica gel heating ring 21 on the outside to avoid condensation of the steam on the wall of the experimental cavity 22 after the steam re-enters the experimental cavity 22. The experimental cavity 22 is wrapped with a heat preservation material on the outside to reduce heat loss, and is also wrapped with a heat preservation material on the inside except the non-test condensation surface to reduce heat exchange.

[0043] The ceramic heating ring 2 and the silica gel heating ring 21 are monitored by a temperature controller in real time to prevent overheating, and the superheated steam is controlled by the heating temperature.

[0044] Please refer to Figure 1 、 Figure 2 In one embodiment, the condensing pipe 8 is provided with a clamp joint 10 between the two ends and the water circulation pipeline.

[0045] In this embodiment, the condensing pipe 8 is replaced by the clamp joint 10 to facilitate experiments on single pipes, pipe bundles of different structures, sizes, and placement angles. Different condensing pipes 8 can be replaced by the clamp joint 10. The outer cavity can be connected with any pipeline wrapped with heat insulation cotton. The cooling water enters the experimental cavity 22 through the water inlet pipeline and flows out through the water outlet to form a circulation loop.

[0046] Experimental process: First, add sufficient deionized water to the constant temperature water tank 16, start the circulating water pump 15, set the specified temperature to a stable state, and then allow the constant temperature cooling water to circulate in the pipeline through the circulating water pump 15, flow meter 19, and cooling water ball valve 20 in sequence. At the same time, the flow rate is controlled by adjusting the circulating water pump 15, and the flow meter 19 instantly records the cooling water flow rate.

[0047] Deionized water is added to steam generator 1, which is then started. Once the steam reaches the set pressure, the top exhaust valve is repeatedly opened to expel the air, ensuring stable boiling. A certain mass of nanoparticles is placed in nanoparticle blender 4, and the ceramic heating coil 2 is preheated to heat the pipeline to prevent steam condensation.

[0048] The silica gel heating ring 21 on the outer wall of the experimental cavity 22 is turned on to reach a predetermined temperature to prevent the steam from condensing on the wall of the experimental cavity 22 and causing errors.

[0049] Close the experimental chamber 22, start the vacuum pump 14 first, then open the exhaust ball valve 13, and evacuate the inside of the experimental chamber 22. After the pressure reaches below the set pressure value, the digital pressure switch 6 feedbacks a signal to close the exhaust solenoid valve 12 on the exhaust pipe, then close the exhaust ball valve 13, and finally turn off the vacuum pump 14.

[0050] Open the ball valve 3 on the air inlet line to introduce steam into the experimental chamber 22. The steam entrains the nanoparticles through the pipeline and the nanoparticle blender 4 to generate nano steam. When the pressure in the experimental chamber 22 reaches the set value, the digital pressure switch 6 feeds back a signal to instantly close the air supply solenoid valve 5 on the air supply line, so that the pressure in the experimental chamber 22 is kept at a constant value.

[0051] During the experiment, the pressure set on the digital pressure switch 6 and the temperature set on the silicone heating coil 21 were adjusted to measure the nano-steam condensation phenomenon and its heat transfer characteristics under different pressures and superheat levels. The superheated nano-steam exchanged heat through the exposed portion of the condenser tube 8, which was not covered by the insulation material. After the steam exchanged heat, the condensate dripped into the experimental chamber 22.

[0052] After the experiment, the chamber door is opened, the condenser 8 is replaced, the nano steam condensate is collected, the processing data is saved, the circulating water pump 15, the constant temperature water tank 16 and the steam generator 1 are turned off, the experimental table is cleaned and drained, and the insulation cotton and thermal insulation material are replaced to ensure that there are no residual nanoparticles inside the experimental chamber 22, the nanoparticle blender 4 and the steam generator 1, and the inside of the experimental chamber 22 is dried for the next experiment.

[0053] The present invention can study the condensation phenomenon, heat transfer coefficient and deposition of nano steam of different types and concentrations; study the condensation phenomenon, heat transfer coefficient and deposition of nano steam on single tubes and tube bundles with different structures, sizes and placement angles; and study the condensation phenomenon, heat transfer coefficient and deposition of nano steam under different superheats and steam pressures.

[0054] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be embraced herein, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

[0055] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A visualization experimental system based on nano steam condensation, characterized in that: It includes a steam circulation module, a water circulation module, a data acquisition module, a control module, an experimental cavity, a vacuum pump and a condenser. The experimental cavity is equipped with a condenser, which is connected to the water circulation module. The water circulation module is used to circulate cooling water in the condenser. The vacuum pump is connected to the experimental cavity and is used to provide the pressure required for the experiment. The steam circulation module includes a steam generator and a nanoparticle blender. The steam generator is filled with water, and the nanoparticle blender is filled with nanoparticles. The steam circulation module is used to mix the steam generated by the steam generator with the nanoparticles and then pass them into the experimental cavity. The steam circulation module is connected to the experimental cavity and circulates; The data acquisition module is used to collect the pressure data in the experimental cavity, the water inlet and outlet temperature data, the steam temperature data, the condenser surface temperature data, the water flow rate and the condensation image of the experimental cavity; The control module is connected to the data acquisition module, and the control module is used to control the pressure of the experimental cavity through the data acquisition module.

2. A visualization experiment system based on nano-steam condensation according to claim 1, characterized in that: The water circulation module includes a circulating water pump and a constant temperature water tank, and the circulating water pump is connected to the constant temperature water tank.

3. A visualization experiment system based on nano-steam condensation according to claim 1 or 2, characterized in that: Valves are installed on the gas supply pipeline, exhaust pipeline and water circulation pipeline.

4. A visualization experiment system based on nano-steam condensation according to claim 3, characterized in that: Solenoid valves are installed on both the air supply pipeline and the exhaust pipeline, and the solenoid valves are controlled by a control module.

5. The visualization experiment system based on nano steam condensation according to claim 1, characterized in that: The nano-particle blender and the steam generator are provided with a heating element wrapped around the outer peripheral surface of the discharge pipeline.

6. The visualization experiment system based on nano-steam condensation according to claim 1, characterized in that: The outside of the experimental cavity is wrapped with a heating element, and the inside and outside of the experimental cavity are provided with a heat-insulating layer.

7. The visualization experiment system based on nano-steam condensation according to claim 1, characterized in that: Compression fittings are installed between the two ends of the condenser and the water circulation pipeline.

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