Experimental system for simulating ultralow temperature environment

Abstract

The invention discloses a simulated ultralow temperature environment experiment system, and belongs to the technical field of environment simulation and low temperature experiments, the simulated ultralow temperature environment experiment system comprises an environment simulation tank body, a heat exchange unit and a liquid nitrogen supply unit, the interior of the environment simulation tank body is an experiment space needing refrigeration, and the heat exchange unit is located in the environment simulation tank body; the liquid nitrogen supply unit is used for providing liquid nitrogen, and the output end of the liquid nitrogen supply unit is used for communicating with a refrigerant inlet of the heat exchange unit. The experiment system runs only by depending on a single cold source of liquid nitrogen, the running energy consumption is remarkably reduced, the size and shape of the environment simulation tank body can be flexibly designed and selected according to experiment requirements, the application scene is greatly expanded, the cold source is continuously supplied to the heat exchange unit arranged in the environment simulation tank body through the liquid nitrogen supply unit, and the experiment efficiency is improved. A stable and uniform ultralow-temperature gas phase environment can be created and maintained in the tank body, and a reliable guarantee is provided for an experiment.

Description

Technical Field

[0001] This invention relates to the field of environmental simulation and low-temperature experimental technology, and in particular to an experimental system for simulating ultra-low temperature environments. Background Technology

[0002] In the research and testing of materials science, physical chemistry, aerospace and electronic components, it is often necessary to conduct experiments in ultra-low temperature environments to study the performance and reliability of materials or products under extreme conditions.

[0003] Currently, the main technical means to achieve ultra-low temperature environments are as follows: First, using large-scale dedicated low-temperature test chambers. Although large-scale low-temperature test chambers can provide a stable low-temperature environment, their equipment purchase cost is high, their operating energy consumption is huge, their system structure is complex and their footprint is large, and their flexibility is poor, making it difficult to meet the needs of temporary, low-cost or specific-size experiments. Second, simple low-temperature devices based on air cooling, water cooling or conventional compressor refrigeration. Although such solutions lower the equipment threshold to a certain extent, their cooling capacity is limited, and the lowest temperature is usually difficult to reach the deep low-temperature environment below -160℃. In addition, they have inherent defects such as slow cooling rate, poor temperature uniformity in the chamber, and insufficient temperature control accuracy, which seriously affect the accuracy and repeatability of experimental data.

[0004] Therefore, there is an urgent need in this field for an experimental system that can overcome the above-mentioned defects, construct ultra-low temperature environments at room temperature, and combine low cost, high flexibility and environmental stability. Summary of the Invention

[0005] The purpose of this invention is to provide an experimental system for simulating ultra-low temperature environments to solve the problems existing in the prior art. It can construct ultra-low temperature environments at room temperature and has the advantages of low cost, high flexibility and environmental stability.

[0006] To achieve the above objectives, the present invention provides the following solution: This invention provides a simulated ultra-low temperature environment experimental system, including an environmental simulation tank, a heat exchange unit, and a liquid nitrogen supply unit. The interior of the environmental simulation tank is an experimental space that needs to be cooled, and the heat exchange unit is located inside the environmental simulation tank. The liquid nitrogen supply unit is used to supply liquid nitrogen, and the output end of the liquid nitrogen supply unit is connected to the refrigerant inlet of the heat exchange unit.

[0007] As one embodiment, the liquid nitrogen supply unit includes a liquid nitrogen storage mechanism and a power mechanism. The liquid nitrogen storage mechanism is used to store liquid nitrogen, and the bottom liquid cavity of the liquid nitrogen storage mechanism is connected to the refrigerant inlet of the heat exchange unit. The power mechanism is used to drive the liquid nitrogen in the liquid nitrogen storage mechanism into the heat exchange unit.

[0008] As one implementation, the power mechanism is a foot-operated self-pressurizing liquid nitrogen pump or an electric self-pressurizing liquid nitrogen pump.

[0009] As one embodiment, the power mechanism is an air pump, the output end of which is connected to the gas phase space at the top of the liquid nitrogen storage mechanism, and is used to pressurize the liquid nitrogen storage mechanism, thereby forcing liquid nitrogen from the bottom liquid cavity into the heat exchange unit.

[0010] In one embodiment, the air pump is connected to the liquid nitrogen supply unit via a ventilation hose.

[0011] As one embodiment, a pressure regulating valve is connected in series on the ventilation hose to maintain and regulate the gas phase pressure in the liquid nitrogen supply unit.

[0012] As one embodiment, it also includes a liquid nitrogen reflux collection unit, the input end of which is connected to the refrigerant outlet of the heat exchange unit.

[0013] As one embodiment, the heat exchange unit is a tubular heat exchanger.

[0014] In one embodiment, the tubular heat exchanger has spiral-shaped pipes.

[0015] In one embodiment, the tubular heat exchanger uses copper tubing.

[0016] The present invention achieves the following technical effects compared to the prior art: The experimental system of this invention consists of an environmental simulation tank, a built-in heat exchange unit, and an independent liquid nitrogen supply unit. The system relies solely on liquid nitrogen as a cold source, eliminating the need for high-power components such as compressors, thus significantly reducing energy consumption. Furthermore, the modular and simplified design greatly reduces manufacturing costs and subsequent maintenance expenses. The size and shape of the environmental simulation tank can be flexibly designed and selected according to experimental needs, no longer limited to fixed-specification commercial enclosures. The entire experimental system requires no professional installation and can be quickly deployed in conventional laboratory environments, flexibly constructing low-temperature environments as needed, greatly expanding application scenarios. This invention continuously supplies a cold source to the heat exchange unit located inside the environmental simulation tank through the liquid nitrogen supply unit, utilizing the principle of heat exchange to uniformly and controllably cool the space inside the tank. This creates and maintains a stable and uniform ultra-low temperature gaseous environment within the tank, providing reliable assurance for experiments. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a simulated ultra-low temperature environment experimental system according to an embodiment of the present invention; The components include: 1. Liquid nitrogen reflux collection unit; 2. Environmental simulation tank; 3. Heat exchange unit; 4. Liquid nitrogen storage mechanism; and 5. Electric self-pressurizing liquid nitrogen pump. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The purpose of this invention is to provide an experimental system for simulating ultra-low temperature environments to solve the problems existing in the prior art. It can construct ultra-low temperature environments at room temperature and has the advantages of low cost, high flexibility and environmental stability.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1As shown, this invention provides a simulated cryogenic environment experimental system, including an environmental simulation tank 2, a heat exchange unit 3, and a liquid nitrogen supply unit. The interior of the environmental simulation tank 2 is the experimental space requiring cooling, and the heat exchange unit 3 is located inside the environmental simulation tank 2. The liquid nitrogen supply unit provides liquid nitrogen, and its output is connected to the refrigerant inlet of the heat exchange unit 3. The experimental system of this invention consists of the environmental simulation tank 2, the built-in heat exchange unit 3, and the independent liquid nitrogen supply unit. The system relies solely on liquid nitrogen as a cold source, eliminating the need for high-power components such as compressors, thus significantly reducing energy consumption. This invention sets up three independent functional modules: the environmental simulation tank, the liquid nitrogen supply unit, and the heat exchange unit. These modules are connected through standardized interfaces and can be freely combined and replaced according to specific experimental needs. This facilitates the mass production of standard modules to reduce the manufacturing cost of individual components. In case of damage, only the faulty module needs to be replaced, rather than the entire machine requiring repair. Furthermore, users can upgrade specific modules according to experimental needs. This modular and simplified design significantly reduces the manufacturing cost of the equipment itself and subsequent maintenance costs. In this invention, the size and shape of the environmental simulation tank 2 can be flexibly designed and selected according to experimental needs, no longer limited to fixed-specification commercial enclosures. The entire experimental system requires no professional installation and can be quickly deployed in conventional laboratory environments. It can flexibly construct low-temperature environments as needed, greatly expanding application scenarios. This invention continuously supplies a cold source to the heat exchange unit 3 placed inside the environmental simulation tank 2 through a liquid nitrogen supply unit. Utilizing the principle of heat exchange, it uniformly and controllably cools the space inside the tank, creating and maintaining a stable and uniform ultra-low temperature gaseous environment inside the tank, providing reliable protection for experiments.

[0023] Optionally, a quick connector is provided between the output end of the liquid nitrogen supply unit and the refrigerant inlet of the heat exchange unit 3. The male and female ends of the quick connector are each equipped with a self-sealing valve core. When the quick connector is disconnected, the valve cores on both sides automatically close to prevent liquid nitrogen leakage; when connected, the valve cores on both sides open to allow passage. This design enables rapid separation and connection between the liquid nitrogen supply unit and the environmental simulation tank 2, improving the flexibility of system deployment while effectively preventing liquid nitrogen waste and safety risks during disassembly.

[0024] Optionally, the environmental simulation tank 2 adopts a double-walled structure with a high-vacuum interlayer and multiple layers of heat-insulating and reflective materials on the outer surface of the inner wall. This composite insulation structure minimizes heat exchange between the inside and outside of the environmental simulation tank 2, significantly reducing the liquid nitrogen consumption rate and enabling longer-term maintenance of the ultra-low temperature environment. Simultaneously, observation windows are provided on the top and side walls of the tank. These windows utilize multi-layered hollow glass with dry inert gas filling the interlayer to meet the needs of visual monitoring during the experiment while ensuring good thermal insulation performance.

[0025] In one embodiment, the liquid nitrogen supply unit includes a liquid nitrogen storage mechanism 4 and a power mechanism. The liquid nitrogen storage mechanism 4 is used to store liquid nitrogen, and its bottom liquid chamber is connected to the refrigerant inlet of the heat exchange unit 3. The power mechanism is used to drive the liquid nitrogen in the liquid nitrogen storage mechanism 4 into the heat exchange unit 3. Through the independently configured liquid nitrogen storage mechanism 4 and power mechanism, the safe storage and controllable transportation of liquid nitrogen are achieved.

[0026] Optionally, a pressure sensor is installed inside the liquid nitrogen storage mechanism 4 and connected to a controller to form a closed-loop control, thereby realizing automatic monitoring and feedback adjustment of the pressurization pressure and improving the system's automation level and pressure control accuracy.

[0027] Optionally, the top of the liquid nitrogen storage mechanism 4 is equipped with a safety pressure relief valve to effectively prevent safety hazards caused by abnormal pressure rise due to liquid nitrogen vaporization, and ensure the safe and reliable operation of the system.

[0028] Optionally, the outer wall of the liquid nitrogen storage mechanism 4 is provided with a vacuum insulation layer, which significantly reduces the heat transfer from the external environment, reduces the natural evaporation loss of liquid nitrogen, and extends the effective working time after a single filling.

[0029] As one implementation, the power mechanism is a foot-operated self-pressurizing liquid nitrogen pump or an electric self-pressurizing liquid nitrogen pump 5. Direct drive using a foot-operated self-pressurizing liquid nitrogen pump or an electric self-pressurizing liquid nitrogen pump 5 results in high delivery efficiency and fast system response.

[0030] Optionally, the components of the liquid nitrogen pump that come into contact with liquid nitrogen are made of austenitic stainless steel or aluminum alloy and are equipped with a double-end dry gas seal suitable for cryogenic environments.

[0031] Optionally, the outlet pipeline of the liquid nitrogen pump is equipped with a flow regulating valve, which can precisely control the cooling capacity input to the heat exchange unit 3 by adjusting the liquid nitrogen flow rate, thereby achieving fine control of the temperature inside the environmental simulation tank 2.

[0032] In one embodiment, the power mechanism is an air pump, the output end of which is connected to the gas phase space at the top of the liquid nitrogen storage unit 4. This air pump is used to pressurize the liquid nitrogen storage unit 4, thereby forcing liquid nitrogen from the bottom liquid chamber into the heat exchange unit 3. By using air pressure to drive the pump, direct contact between the pump body and liquid nitrogen is avoided, which reduces the system's dependence on cryogenic pumps and associated costs.

[0033] Optionally, the air pump is an oil-free air compressor, which can provide clean pressurized gas to ensure the purity of liquid nitrogen and the cleanliness of the system.

[0034] Optionally, a drying filter can be installed on the pipeline between the air pump and the liquid nitrogen storage unit 4 to further remove moisture and impurities from the compressed air, preventing freezing and blockage of the pipeline or affecting heat exchange efficiency in ultra-low temperature environments.

[0035] In one implementation, the air pump and the liquid nitrogen supply unit are connected via a ventilation hose. This hose connection facilitates arrangement and adjustment, improving the flexibility of system assembly.

[0036] Optionally, the ventilation hose is a low-temperature resistant and pressure-resistant metal braided hose, ensuring connection reliability and long service life under ultra-low temperatures and certain pressures, avoiding the problem of low-temperature embrittlement of ordinary rubber hoses.

[0037] Optionally, quick-connect couplings are used at the interfaces between the ventilation hose and the air pump and liquid nitrogen storage mechanism 4 to facilitate the quick connection, disassembly and maintenance of various system components, thereby improving the convenience of system deployment and adjustment.

[0038] As one implementation, a pressure regulating valve is connected in series on the ventilation hose to maintain and regulate the gas phase pressure within the liquid nitrogen supply unit.

[0039] Optionally, the pressure regulating valve is a precision pressure regulating valve with a pressure gauge, which allows operators to visually monitor and accurately set the working pressure, ensuring the stability of the liquid nitrogen supply pressure and thus guaranteeing a constant cooling rate.

[0040] As one implementation, it also includes a liquid nitrogen reflux collection unit 1. The input end of the liquid nitrogen reflux collection unit 1 is used to connect with the refrigerant outlet of the heat exchange unit 3 to realize the safe collection and treatment of liquid nitrogen after heat exchange, and avoid the waste and safety hazards caused by direct discharge.

[0041] Optionally, the liquid nitrogen reflux collection unit 1 is a double-layered vacuum insulated container that efficiently collects and temporarily stores the low-temperature gas-liquid mixture flowing out of the heat exchange unit 3, maximizing the recovery of residual cold energy and reducing the waste of cold source.

[0042] Optionally, the exhaust port of the liquid nitrogen reflux collection unit 1 is connected to a tail gas treatment device to safely divert or harmlessly treat the evaporated nitrogen, preventing the risk of oxygen deficiency that may result from nitrogen accumulation in the laboratory.

[0043] As one embodiment, the heat exchange unit 3 is a tubular heat exchanger. The tubular heat exchanger has a simple and reliable structure, a large heat exchange area, and is easy to process and manufacture.

[0044] Optionally, the tubular heat exchanger can be fixed to the inner wall of the environmental simulation tank 2 by a detachable clamp or bracket, which facilitates the installation and maintenance of the heat exchange unit 3 or the replacement of heat exchangers of different specifications according to the test requirements.

[0045] Optionally, the tubular heat exchanger is fixedly installed via its inlet and outlet pipes. Specifically, two through holes are made on the top cover plate of the environmental simulation tank 2, and the ends of the inlet and outlet pipes of the tubular heat exchanger pass through the corresponding through holes and extend to the outside of the environmental simulation tank 2. Through the fit between the tube body and the through holes, or with the aid of fasteners such as sealing sleeves and lock nuts, the tubular heat exchanger can be stably suspended in the internal space of the environmental simulation tank 2. This installation method eliminates the need for complex supports inside the tank, resulting in an extremely simple structure. This not only reduces manufacturing costs but also facilitates the overall disassembly, maintenance, and replacement of the heat exchanger, greatly improving the maintainability and operational flexibility of the system.

[0046] Optionally, the tubular heat exchanger consists of multiple parallel pipes connected in parallel. Each pipe has a distributor at its inlet and a collector at its outlet to ensure uniform flow distribution of liquid nitrogen within the pipes, improving overall heat exchange efficiency and temperature uniformity within the tank. Alternatively, the tubular heat exchanger can have spiral-shaped pipes, maximizing the heat exchange area within a limited space and significantly improving heat exchange efficiency and temperature uniformity. Specifically, the spiral shape and distribution density of the tubular heat exchanger can be adaptively adjusted according to the internal spatial structure of the environmental simulation tank 2 and the size and shape of the test object. By changing the spiral pitch, coil spacing, or local winding method, targeted heat exchange can be enhanced in specific areas within the environmental simulation tank 2 or on the surface of the test object. This ensures overall temperature uniformity while flexibly adapting to test objects of different volumes, shapes, and heat load distributions, significantly improving the system's adaptability to different experimental scenarios.

[0047] Optionally, the outer wall of the spiral pipe is provided with fins, which can significantly increase the heat exchange area, enhance the heat exchange on the air side outside the pipe, and accelerate the cooling process inside the environmental simulation tank 2.

[0048] As one implementation method, the tubular heat exchanger uses copper tubes. Copper's excellent thermal conductivity ensures efficient transfer of cold energy, while the material also has good mechanical stability at low temperatures.

[0049] Optionally, the inner wall of the copper tube is polished. The high thermal conductivity of the copper tube, combined with the smooth inner wall, can minimize heat transfer resistance and flow resistance, ensuring efficient heat transfer and smooth delivery.

[0050] The experimental process of the simulated ultra-low temperature environment experimental system according to an embodiment of the present invention is as follows: Before the experiment begins, the sample to be tested is placed in the environmental simulation tank 2. The liquid nitrogen storage mechanism 4 is filled with liquid nitrogen, and a liquid nitrogen pump or a gas pump is selected as the power mechanism according to the experimental requirements. When using the gas pump, the gas pump is turned on and pressurized to the gas phase space at the top of the liquid nitrogen storage mechanism 4 through the venting hose, and the pressure is adjusted to the set value through the pressure regulating valve; when using the liquid nitrogen pump, the liquid nitrogen pump is started directly. Driven by the set pressure, liquid nitrogen flows out from the liquid cavity at the bottom of the liquid nitrogen storage mechanism 4 and is transported to the tubular heat exchanger located in the environmental simulation tank 2 through the cryogenic pipeline. During the flow of liquid nitrogen in the spiral copper heat exchange pipeline, the liquid nitrogen undergoes sufficient heat exchange with the internal space of the tank through the pipe wall, causing the temperature inside the tank to drop rapidly. The cryogenic fluid after heat exchange is discharged into the liquid nitrogen reflux collection unit 1 through the pipeline. Through continuous circulation, a stable ultra-low temperature environment below -160°C is formed and maintained in the environmental simulation tank 2. During the experiment, the cooling rate and final steady-state temperature can be precisely controlled by adjusting the power of the power mechanism or the pressure of the pressure regulating valve to meet the low-temperature performance testing requirements of different materials.

[0051] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A simulated ultra-low temperature environment experimental system, characterized in that, include: The environmental simulation tank (2) contains an experimental space that requires cooling. A heat exchange unit (3) is located inside the environmental simulation tank (2); A liquid nitrogen supply unit is used to supply liquid nitrogen, and the output end of the liquid nitrogen supply unit is used to connect with the refrigerant inlet of the heat exchange unit (3).

2. The simulated ultra-low temperature environment experimental system according to claim 1, characterized in that: The liquid nitrogen supply unit includes a liquid nitrogen storage mechanism (4) and a power mechanism. The liquid nitrogen storage mechanism (4) is used to store liquid nitrogen. The bottom liquid cavity of the liquid nitrogen storage mechanism (4) is connected to the refrigerant inlet of the heat exchange unit (3). The power mechanism is used to drive the liquid nitrogen in the liquid nitrogen storage mechanism (4) into the heat exchange unit (3).

3. The simulated ultra-low temperature environment experimental system according to claim 2, characterized in that: The power mechanism is a foot-operated self-pressurizing liquid nitrogen pump or an electric self-pressurizing liquid nitrogen pump (5).

4. The simulated ultra-low temperature environment experimental system according to claim 2, characterized in that: The power mechanism is an air pump. The output end of the air pump is connected to the gas phase space at the top of the liquid nitrogen storage mechanism (4) and is used to pressurize the liquid nitrogen storage mechanism (4) so ​​as to pressurize the liquid nitrogen from the bottom liquid cavity into the heat exchange unit (3).

5. The simulated ultra-low temperature environment experimental system according to claim 4, characterized in that: The air pump is connected to the liquid nitrogen supply unit via a ventilation hose.

6. The simulated ultra-low temperature environment experimental system according to claim 5, characterized in that: A pressure regulating valve is connected in series on the ventilation hose to maintain and regulate the gas phase pressure in the liquid nitrogen supply unit.

7. The simulated ultra-low temperature environment experimental system according to claim 1, characterized in that: It also includes a liquid nitrogen reflux collection unit (1), the input end of which is connected to the refrigerant outlet of the heat exchange unit (3).

8. The simulated ultra-low temperature environment experimental system according to claim 1, characterized in that: The heat exchange unit (3) is a tubular heat exchanger.

9. The simulated ultra-low temperature environment experimental system according to claim 8, characterized in that: The tubular heat exchanger has spiral-shaped pipes.

10. The simulated ultra-low temperature environment experimental system according to claim 8 or 9, characterized in that: The tubular heat exchanger uses copper pipes.

Images