Liquid nitrogen refrigeration sample working vehicle with temperature regulation and control function
Through the liquid nitrogen recovery tank and precise control system, the problems of high failure rate, high energy consumption and uncontrollable temperature of low-temperature transfer vehicles are solved, and the precise temperature regulation and drying of condensate are achieved, ensuring that the sample is within a wide temperature range. Safe storage and cooling chamber cleaning.
Patent Information
- Application Number
- CN202411359853.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2024-12-10
AI Technical Summary
The existing low-temperature transfer vehicles have problems such as high failure rate, high energy consumption, uncontrollable temperature maintenance time, unsettlement of temperature, and moldy and odorous condensate inside the cooling box.
A sample working vehicle refrigerated by liquid nitrogen is designed, using a liquid nitrogen recovery tank, temperature sensor, nitrogen concentration detector, rotary driving mechanism and control system. By accurately controlling the injection and vaporization of liquid nitrogen, temperature regulation is achieved and equipped with Electric heaters and mechanical pressure relief valves to dry condensate.
It achieves low failure rate, low energy consumption, controllable temperature and wide temperature setting range, ensuring stable storage of samples in the range of -190℃ to 20℃, and maintaining clean and hygienic interior of the cooling chamber.
Smart Images
Figure CN119099693A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of low-temperature transfer vehicles, and more specifically to the technical field of a sample work vehicle that utilizes liquid nitrogen refrigeration and has temperature control. Background Art
[0002] Hospitals and other biological laboratories need to use sample work vehicles (low-temperature transport vehicles) when transporting and selecting human, animal, plant or part samples. For example, cells, plasma, tissues, etc. need to be in a low-temperature environment during transfer and preservation to ensure the biological activity of biological samples; there are two ways to achieve this in the existing technology. One is to use compressor refrigeration, which has a high failure rate at ultra-low temperatures, large size, heavy and laborious transfer, and high after-sales maintenance costs; the other is to use simple liquid nitrogen refrigeration, which has a simple structure and low failure rate, but it consumes a lot of liquid nitrogen, has low safety, is difficult to control temperature, consumes a lot of liquid nitrogen, and has worrying hygiene problems caused by internal condensation. Regarding the two existing refrigeration methods, specifically:
[0003] Compressor refrigeration: The work vehicle using compressor for cooling is noisy; batteries are needed to power the refrigerator during sample transportation, which makes the equipment large and bulky. In particular, when performing pipe picking operations at ultra-low temperatures below -80°C, the lid needs to be opened, which requires a huge amount of cooling. The refrigeration system is difficult to reach the temperature, the compressor is burdened, the failure rate is high, and the after-sales maintenance costs are high.
[0004] Simple liquid nitrogen refrigeration: Ultra-low temperature work vehicles that use liquid nitrogen as a cooling source usually fill a certain amount of liquid nitrogen at the bottom of the vacuum box, and use the cold energy (latent heat) of the liquid nitrogen phase change to maintain the temperature of the cold cavity. After the liquid nitrogen phase changes to nitrogen, the density decreases and it will be naturally discharged into the environment, resulting in the sensible heat of the cold nitrogen gas not being utilized; the temperature maintenance time cannot be controlled, and usually too much or too little liquid nitrogen is added. Excessive liquid nitrogen cannot be recovered, resulting in a waste of resources; although this simple method of using liquid nitrogen fumigation to cool down has a simple structure and a low failure rate, it consumes a lot of liquid nitrogen.
[0005] The ultra-low temperature work vehicle that uses liquid nitrogen as the cooling source has a simple refrigeration principle. The more liquid nitrogen is added, the lower the temperature is and the longer it is maintained. The less liquid nitrogen is added, the higher the temperature is and the shorter the maintenance time is. However, the vacuum degree of the vacuum box is constantly decreasing, and its thermal insulation performance is also gradually decreasing. Moreover, different vacuum boxes have different decreasing speeds. It is difficult to determine how much liquid nitrogen to use to achieve the required maintenance temperature and duration. Failure to meet the temperature standard will cause irreversible damage to the sample, with extremely serious consequences.
[0006] Ultra-low temperature work vehicles that use liquid nitrogen as a cooling source have no temperature control measures and accuracy. Generally, they simply control the temperature in the cavity below the glass transition temperature (<-136°C), but this cannot be achieved in situations where specific temperature values need to be controlled.
[0007] After the work vehicle is used, a large amount of condensed water will be produced inside the vacuum cooling box due to the low temperature, which will breed bacteria and odor. Summary of the invention
[0008] The purpose of the present invention is to solve the technical problems of high failure rate, high energy consumption, uncontrollable temperature maintenance time, unsettable temperature, and moldy and smelly condensed water in the internal sample storage area of the cooling box in the existing transfer vehicle. The present invention provides a sample work vehicle with temperature control using liquid nitrogen refrigeration. The device is easy to use, has a low failure rate, low energy consumption, controllable temperature, a temperature setting range of -190°C to 20°C, and has a vacuum cooling box internal condensed water drying function and a folding plate.
[0009] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:
[0010] The present invention provides a sample work vehicle with temperature control using liquid nitrogen refrigeration, comprising a vehicle frame, a vehicle compartment arranged on the top of the vehicle frame, and a liquid nitrogen recovery tank arranged inside the vehicle frame, wherein the vehicle compartment comprises a shell opening upward, a cooling box arranged inside the shell, an air duct arranged between the cooling box and the side wall of the shell, and a sealing cover arranged on the top of the cooling box;
[0011] The cooling box is provided with a nitrogen inlet pipe which is connected with the air duct, a second low-temperature solenoid valve is provided on the nitrogen inlet pipe, a low-temperature nitrogen outlet of the nitrogen inlet pipe extends to the bottom of the cooling box, and a first temperature sensor and a nitrogen concentration detector are provided in the cooling box;
[0012] The air duct is provided with a nozzle for spraying liquid nitrogen, a temperature regulating mechanism for vaporizing and regulating the temperature of nitrogen, and a wind wheel for circulating the liquid nitrogen in the air duct, a first low-temperature electromagnetic valve is provided on the connecting pipe of the nozzle, and the wind wheel is driven by a rotating driving mechanism;
[0013] It also includes a control system, and the first low-temperature solenoid valve, the second low-temperature solenoid valve, the first temperature sensor, the second temperature sensor, the nitrogen concentration detector, the rotary drive mechanism, and the temperature regulating mechanism are all electrically connected to the control system; when the temperature in the cooling box drops to the temperature set by the first temperature sensor, due to the reduction in the required cooling capacity, the control system controls the temperature of the temperature regulating mechanism according to the result of the automatic calculation output by the PID according to the set temperature point to achieve dynamic thermal balance.
[0014] Specifically, the operation process is as follows: after the parameters are set, the rotary drive mechanism and the first cryogenic solenoid valve are turned on, and the liquid nitrogen reaches the nozzle through the pipeline to form a mist of liquid nitrogen. At this time, the nitrogen mist is evenly distributed to the entire air duct by the circulating wind generated by the wind wheel and vaporized into nitrogen to achieve cooling using latent heat. However, the vaporized nitrogen in the air duct must not be discharged when it is in a closed state, and the sensible heat of the nitrogen will continue to cool the air duct; at the same time, the cold is also quickly transferred to the inner wall of the cooling box, and the inner wall of the cooling box transfers and radiates the heat to the space in the cooling box. When the temperature in the cooling box drops to the temperature set by the first temperature sensor, due to the reduction in the required cold, the control system controls the output of the electric heater according to the result of the automatic calculation output of the PID according to the set temperature point, achieving a dynamic thermal balance, and finally making the internal temperature uniformity of the cooling box more stable. Since the consumed liquid nitrogen is in a closed environment in the air duct, the latent heat and sensible heat of the liquid nitrogen are both utilized, and the consumption of liquid nitrogen is also reduced, thereby reducing the consumption of liquid nitrogen.
[0015] This solution can quickly cool down, and when the set temperature is reached, the temperature can be kept constant accurately. The work vehicle can maintain a low temperature for a long time, and the temperature control range is larger, which is safer during operation. The folding board can be used to place notebooks or accompanying equipment such as barcode scanners. After the operation, the remaining liquid nitrogen can be recovered, and the internal condensed water of the cooling box can be dried to keep it clean.
[0016] In one embodiment, the shell is a double-layer shell, including an inner shell and an outer shell, and a vacuum insulation layer is formed between the inner shell and the outer shell.
[0017] In one embodiment, a pressure relief valve communicating with the interior of the air duct is disposed on the outer wall of the shell, and the pressure relief valve is a mechanical pressure relief valve.
[0018] Specifically, when the pressure in the air duct exceeds the set value of the mechanical pressure relief valve, the mechanical pressure relief valve opens to release the pressure. A mechanical pressure relief valve is provided on the top of the cooling box to prevent the pressure in the air duct from being too high, which may cause safety hazards.
[0019] In one embodiment, the rotary drive mechanism is a fan, and the fan, the first cryogenic solenoid valve, the second cryogenic solenoid valve, and the mechanical pressure relief valve are located outside the double-layer shell.
[0020] In one embodiment, a liquid nitrogen recovery device connected to the interior of the liquid nitrogen recovery tank is provided in the air duct, and a liquid level sensor electrically connected to the control system is provided in the air duct.
[0021] Specifically, in situations where ultra-low temperatures are required, the refrigeration system will control the first cryogenic solenoid valve to spray a large amount of liquid nitrogen into the air duct, causing liquid nitrogen to accumulate at the bottom of the air duct. In order to prevent the liquid nitrogen height from exceeding a certain amount and affecting the rotating drive mechanism, a liquid level sensor in the air duct is required to monitor the liquid level. When the maximum liquid level setting value is reached, the first cryogenic solenoid valve will be closed.
[0022] In one embodiment, a plurality of heat-conducting baffles are arranged in a criss-cross pattern inside the cooling box, and the plurality of heat-conducting baffles divide the interior of the cooling box into a plurality of cavities.
[0023] Specifically, the inner wall of the cooling box transfers and radiates heat to the space inside the cooling box through the partition. The partition inside the cooling box acts as a cold conduction plate, which makes it easier for the temperature inside the cooling box to reach the required temperature through cold conduction; considering that the interior of the cooling box is initially filled with air, once the internal temperature of the cooling box is lower than 0°C, condensation water is easily generated at the edge. To avoid this, the second low-temperature solenoid valve is opened when the temperature in the air duct begins to drop, so that low-temperature nitrogen enters the inner bottom of the cooling box to remove the air containing water vapor in the cooling box, and finally achieves the goal of quickly cooling the interior of the cooling box and keeping the interior of the cooling box from being easily frozen.
[0024] In one embodiment, the air duct includes a front air duct, a rear air duct, a left air duct, a right air duct and a bottom air duct that are interconnected, and the wind wheel is arranged in any air duct of the front air duct, the rear air duct, the left air duct and the right air duct.
[0025] Specifically, there are air ducts between the five sides of the cooling box except the top and the outer shell, and the wind direction in the air duct is as follows: Figure 1 As shown, the circulating wind generated by the left wind wheel passes through the bottom wind duct to the right wind duct, and then returns to the left wind wheel through the front and rear side wind ducts to form a circulating wind duct.
[0026] In one embodiment, a folding plate capable of flipping 0-90 degrees is provided on the frame.
[0027] Specifically, if Figure 3As shown, the working vehicle of this scheme is safe and temperature-controllable and can carry out tube picking with different temperature requirements for a long time. When the interior of the cooling box quickly reaches the set temperature value (such as -150°C), the cryopreserved tubes can be transferred and selected. During the selection process, the operator can select the cryopreserved tubes in the cryopreservation box inside the cooling box and transfer them to the tube picking basket. In order to reduce the generation of condensed water at the inner edge of the cooling box, the nitrogen concentration detector will open the second low-temperature solenoid valve to introduce low-temperature nitrogen into the interior of the cooling box when it detects that the nitrogen concentration is lower than the set value, so that the interior of the cooling box maintains a certain concentration of nitrogen, which can maintain a low-temperature environment and prevent the generation of excessive condensed water. When the -150°C demand is over, if other temperatures are needed in a short time, the required temperature can be quickly reached through the control system, so that different temperature requirements can be met for continuous use in a short time.
[0028] In one embodiment, the liquid nitrogen recovery device includes a liquid nitrogen recovery port opening upward, the liquid nitrogen recovery port is larger at the top and smaller at the bottom, and the bottom small end of the liquid nitrogen recovery port is provided with at least two drainage ports connected to the inside of the liquid nitrogen recovery port, and a brass joint capable of blocking the liquid nitrogen recovery port is provided in the liquid nitrogen recovery port, and a fiberglass connecting rod is connected to the top of the brass joint, and the top of the connecting rod is connected to a handwheel that drives the liquid nitrogen recovery device to rise and fall through the air duct.
[0029] Specifically, if Figure 4 As shown, the liquid nitrogen in the air duct can be recycled and reused. After using ultra-low temperature, a certain amount of liquid nitrogen will remain at the bottom of the air duct. In order to adhere to the principle of saving and not wasting, you can turn the hand wheel in reverse. Figure 4 The fiberglass connecting rod will move upward to open the liquid outlet, and finally the liquid nitrogen will flow from the pipeline to the liquid nitrogen recovery tank.
[0030] like Figure 5 As shown in the figure, it is an enlarged view of the liquid nitrogen recovery device. When the fiberglass connecting rod rotates upward, the top of the brass joint is separated from the liquid nitrogen recovery device. At this time, the liquid nitrogen will flow from the drain port to the pipeline and finally flow into the liquid nitrogen recovery barrel. After the operation is completed, tighten the handwheel in the forward direction to turn off the liquid nitrogen recovery function in preparation for the next use.
[0031] In one embodiment, the temperature regulating mechanism is an electric heater.
[0032] Specifically, if Figure 6As shown, the electric heater has a drying function. When the internal temperature of the cooling box after use is still at a low temperature, air with water vapor will enter the interior of the cooling box to form condensed water. If the work vehicle is not used for a long time, bacteria will grow inside the cooling box or emit odor. To prevent this, it is necessary to heat and dry the condensed water inside the cooling box. At this time, the electric heater is needed to generate heat, but the heat generation is controlled by PID. The circulating wind generated by the fan makes the temperature in the air duct rise to a maximum of 60°C. When the temperature rises and the pressure in the air duct increases, the mechanical pressure relief valve will be opened for pressure relief. The temperature cannot be too high, otherwise it will affect the vacuum layer. After a period of drying, the interior of the cooling box remains dry, and the hygienic cleanliness of the interior of the cooling box is met.
[0033] The beneficial effects of the present invention are as follows:
[0034] 1. The present invention has a reasonable design, does not use a compressor, uses precise liquid nitrogen refrigeration, and can achieve ultra-low temperature conditions; reduces the volume, noise, and failure rate of the work vehicle, and reduces maintenance costs.
[0035] 2. Use precise liquid nitrogen refrigeration to utilize both the latent heat and sensible heat of liquid nitrogen phase change, and reserve a liquid nitrogen recovery device so that even if a small amount of liquid nitrogen is not vaporized, it can be recovered, thereby reducing the consumption of liquid nitrogen.
[0036] 3. Use precise liquid nitrogen refrigeration to control the action of the first low-temperature solenoid valve according to the measurement and set value of the sensor to achieve the control of the cold chamber temperature and ensure that the internal samples of the vacuum cooling box are at the set temperature at the set time.
[0037] 4. Use precise liquid nitrogen refrigeration to control the action of the first low-temperature solenoid valve according to the measurement and set value of the sensor to achieve the control of the cold chamber temperature. Combined with the output of the electric heater to achieve a dynamic balance, the interior of the vacuum cooling box can be controlled to any constant temperature in the range of -190℃ to 20℃.
[0038] 5. Use electric heater and fan to heat the inside of the vacuum cooling box, dry the inside of the cooling box, and keep the inside clean and hygienic.
[0039] 6. Use the folding board to place portable devices such as notebooks or barcode scanners.
[0040] 7. The combined design of the second cryogenic solenoid valve and the nitrogen concentration detector is used to fill the cooling box with nitrogen, thereby preventing the sample and the interior of the cooling box from freezing due to the inflow of cold air. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.
[0042] Figure 1 It is a schematic diagram of the structure of the present invention;
[0043] Figure 2 yes Figure 1 A top view of
[0044] Figure 3 yes Figure 1 Schematic diagram of the layout structure when in use;
[0045] Figure 4 This is a schematic diagram of liquid nitrogen recovery;
[0046] Figure 5 It is a structural schematic diagram of a liquid nitrogen recovery device;
[0047] Figure 6 This is a schematic diagram of the air duct when it is heated;
[0048] Figure markings: 1-nitrogen concentration detector, 2-first temperature sensor, 3-hand wheel, 4-second temperature sensor, 5-liquid level sensor, 6-liquid nitrogen recovery device, 7-liquid nitrogen recovery outlet, 8-nozzle, 9-first low-temperature solenoid valve, 10-electric heater, 11-folding plate, 12-fan, 13-mechanical pressure relief valve, 14-wind wheel, 15-second low-temperature solenoid valve, 16-sealing cover. DETAILED DESCRIPTION
[0049] In order to make the technical problems, technical solutions and technical effects of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.
[0050] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0051] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.
[0052] In the description of the embodiments of the present invention, it should be noted that the terms "inside", "outside", "upper", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0053] Example 1
[0054] This embodiment provides a sample work vehicle with temperature control using liquid nitrogen refrigeration, including a vehicle frame, a vehicle compartment arranged on the top of the vehicle frame, and a liquid nitrogen recovery tank arranged inside the vehicle frame, the vehicle compartment includes a shell opening upward, a cooling box arranged in the shell, an air duct arranged between the cooling box and the side wall of the shell, and a sealing cover 16 arranged on the top of the cooling box;
[0055] The cooling box is provided with a nitrogen inlet pipe which is connected to the air duct, a second low-temperature solenoid valve 15 is provided on the nitrogen inlet pipe, a low-temperature nitrogen outlet of the nitrogen inlet pipe extends to the bottom of the cooling box, and a first temperature sensor 2 and a nitrogen concentration detector 1 are provided in the cooling box;
[0056] The air duct is provided with a nozzle 8 for spraying liquid nitrogen, a temperature regulating mechanism for vaporizing and regulating the temperature of nitrogen, and a wind wheel 14 for circulating liquid nitrogen in the air duct. A first low-temperature electromagnetic valve 9 is provided on the connecting pipe of the nozzle 8, and the wind wheel 14 is driven by a rotating driving mechanism.
[0057] It also includes a control system, and the first low-temperature solenoid valve 9, the second low-temperature solenoid valve 15, the first temperature sensor 2, the second temperature sensor 4, the nitrogen concentration detector 1, the rotation drive mechanism, and the temperature adjustment mechanism are all electrically connected to the control system; when the temperature in the cooling box drops to the temperature set by the first temperature sensor 2, due to the reduction in the required cooling capacity, the control system controls the temperature of the temperature adjustment mechanism according to the result of the automatic calculation output by the PID according to the set temperature point to achieve dynamic thermal balance.
[0058] Specifically, the operation process is as follows: after the parameters are set, the rotary drive mechanism and the first low-temperature electromagnetic valve 9 are turned on, and the liquid nitrogen reaches the nozzle 8 through the pipeline to form a mist of liquid nitrogen. At this time, the nitrogen mist is evenly distributed to the entire air duct by the circulating wind generated by the wind wheel 14 and vaporized into nitrogen to achieve cooling using latent heat. However, the vaporized nitrogen in the air duct cannot be discharged when it is in a closed state, and the sensible heat of the nitrogen will continue to cool the air duct; at the same time, the cold amount is also quickly transferred to the inner wall of the cooling box, and the inner wall of the cooling box transfers and radiates the heat to the space in the cooling box. When the temperature in the cooling box drops to the temperature set by the first temperature sensor 2, due to the reduction in the required cold amount, the control system controls the output of the electric heater 10 according to the result of the automatic calculation output of the PID according to the set temperature point, achieving a dynamic thermal balance, and finally making the internal temperature uniformity of the cooling box more stable. Since the consumed liquid nitrogen is in a closed environment in the air duct, the latent heat and sensible heat of the liquid nitrogen are both utilized, and the consumption of liquid nitrogen is also reduced, thereby reducing the consumption of liquid nitrogen.
[0059] This solution can quickly cool down, and when the set temperature is reached, the temperature can be kept constant accurately. The work vehicle can maintain a low temperature for a long time, and the temperature control range is larger, which is safer during operation. The folding plate 11 can be used to place portable devices such as notebooks or barcode scanners. After the operation, the remaining liquid nitrogen can be recovered, and the internal condensed water of the cooling box can be dried to keep it clean.
[0060] Example 2
[0061] This embodiment is further optimized on the basis of embodiment 1, specifically:
[0062] The shell is a double-layer shell, comprising an inner shell and an outer shell, and a vacuum insulation layer is formed between the inner shell and the outer shell.
[0063] A pressure relief valve connected to the inside of the air duct is arranged on the outer wall of the shell, and the pressure relief valve is a mechanical pressure relief valve 13 .
[0064] Specifically, the mechanical pressure relief valve 13 opens to release pressure when the pressure in the air duct exceeds the set value of the mechanical pressure relief valve 13. The mechanical pressure relief valve 13 is provided above the interior of the cooling box to prevent the pressure in the air duct from being too high, which may cause safety hazards.
[0065] Example 3
[0066] This embodiment is further optimized on the basis of embodiment 1, specifically:
[0067] The rotary drive mechanism is a fan 12 , and the fan 12 , the first cryogenic solenoid valve 9 , the second cryogenic solenoid valve 15 and the mechanical pressure relief valve 13 are located outside the double-layer shell.
[0068] A liquid nitrogen recovery device 6 connected to the interior of the liquid nitrogen recovery tank is arranged in the air duct, and a liquid level sensor 5 electrically connected to the control system is arranged in the air duct.
[0069] Specifically, in situations where ultra-low temperatures are required, the refrigeration system will control the first cryogenic solenoid valve 9 to spray a large amount of liquid nitrogen into the air duct, causing liquid nitrogen to accumulate at the bottom of the air duct. In order to prevent the liquid nitrogen height from exceeding a certain amount and affecting the rotating drive mechanism, a liquid level sensor 5 in the air duct is required to monitor the liquid level. When the maximum liquid level setting value is reached, the first cryogenic solenoid valve 9 will be closed.
[0070] Example 4
[0071] This embodiment is further optimized on the basis of embodiment 3, specifically:
[0072] A plurality of heat-conducting baffles are arranged in a criss-cross pattern inside the cooling box, and the plurality of heat-conducting baffles divide the interior of the cooling box into a plurality of cavities.
[0073] Specifically, the inner wall of the cooling box transfers and radiates heat to the space inside the cooling box through the partition. The partition inside the cooling box acts as a cold conduction plate, and the temperature inside the cooling box is easier to reach the required temperature through cold conduction; considering that the interior of the cooling box is initially filled with air, once the internal temperature of the cooling box is lower than 0°C, condensation water is easily generated at the edge. To avoid this, the second low-temperature solenoid valve 15 is opened when the temperature in the air duct begins to drop, so that low-temperature nitrogen enters the inner bottom of the cooling box to remove the air containing water vapor in the cooling box, and finally achieves the goal of quickly cooling the interior of the cooling box and keeping the interior of the cooling box from being easily frozen.
[0074] Example 5
[0075] This embodiment is further optimized on the basis of Embodiment 3 or Embodiment 4, specifically:
[0076] The air duct includes a front air duct, a rear air duct, a left air duct, a right air duct and a bottom air duct which are interconnected, and the wind wheel 14 is arranged in any air duct of the front air duct, the rear air duct, the left air duct and the right air duct.
[0077] Specifically, there are air ducts between the five sides of the cooling box except the top and the outer shell, and the wind direction in the air duct is as follows: Figure 1 As shown, the circulating wind generated by the left wind wheel 14 passes through the bottom wind duct to the right wind duct, and then returns to the left wind wheel 14 through the front and rear side wind ducts, forming a circulating wind duct.
[0078] The frame is provided with a folding plate 11 which can be turned over by 0-90 degrees.
[0079] Specifically, if Figure 3As shown, the working vehicle of this scheme is safe and temperature-controllable and can select tubes with different temperature requirements for a long time. When the interior of the cooling box quickly reaches the set temperature value (such as -150°C), the cryopreserved tubes can be transferred and selected. During the selection process, the operator can select the cryopreserved tubes in the cryopreservation box inside the cooling box and transfer them to the tube selection basket. In order to reduce the generation of condensed water at the inner edge of the cooling box, the nitrogen concentration detector 1 will open the second low-temperature solenoid valve 15 to introduce low-temperature nitrogen into the interior of the cooling box when it detects that the nitrogen concentration is lower than the set value, so that the interior of the cooling box maintains a certain concentration of nitrogen, which can maintain a low-temperature environment and prevent excessive condensed water. When the -150°C demand is over, if other temperatures are needed in a short time, the required temperature can be quickly reached through the control system, so that different temperature requirements can be met for continuous use in a short time.
[0080] Example 6
[0081] This embodiment is further optimized on the basis of Embodiment 3, Embodiment 4 or Embodiment 5, specifically:
[0082] The liquid nitrogen recovery device 6 includes a liquid nitrogen recovery port opening upward, the liquid nitrogen recovery port is larger at the top and smaller at the bottom, and the bottom small end of the liquid nitrogen recovery port is provided with at least two drainage ports connected to the inside of the liquid nitrogen recovery port, and a brass joint capable of blocking the liquid nitrogen recovery port is provided in the liquid nitrogen recovery port, and a glass fiber reinforced plastic connecting rod is connected to the top of the brass joint, and the top of the connecting rod is connected to a hand wheel 3 that drives the liquid nitrogen recovery device 6 to rise and fall through the air duct.
[0083] Specifically, if Figure 4 As shown, the liquid nitrogen in the air duct can be recycled and reused. After using the ultra-low temperature, a certain amount of liquid nitrogen will remain at the bottom of the air duct. In order to adhere to the principle of saving and not wasting, the hand wheel 3 can be turned in reverse. Figure 4 The fiberglass connecting rod will move upward to open the liquid outlet, and finally the liquid nitrogen will flow from the pipeline to the liquid nitrogen recovery tank.
[0084] like Figure 5 As shown, it is an enlarged view of the liquid nitrogen recovery device 6. When the fiberglass connecting rod rotates upward to drive the top of the brass joint to separate from the liquid nitrogen recovery device 6, the liquid nitrogen will flow from the drain port to the pipeline and finally flow into the liquid nitrogen recovery barrel. After the operation is completed, the hand wheel 3 is tightened in the forward direction to turn off the liquid nitrogen recovery function to prepare for the next use.
[0085] Example 7
[0086] This embodiment is further optimized on the basis of embodiment 6, specifically:
[0087] The temperature adjustment mechanism is an electric heater 10 .
[0088] Specifically, if Figure 6 As shown, the electric heater 10 has a drying function. When the internal temperature of the cooling box after use is still at a low temperature, air with water vapor will enter the interior of the cooling box to form condensed water. If the work vehicle is not used for a long time, bacteria will grow inside the cooling box or emit odor. To prevent this, the condensed water inside the cooling box needs to be heated and dried. At this time, the electric heater 10 needs to generate heat, but the heat generation is controlled by PID. The circulating wind generated by the fan 12 makes the temperature in the air duct rise to a maximum of 60°C. When the temperature rises and the pressure in the air duct increases, the mechanical pressure relief valve 13 will be opened for pressure relief. The temperature cannot be too high, otherwise it will affect the vacuum layer. After a period of drying, the interior of the cooling box remains dry, and the sanitation and cleanliness of the interior of the cooling box are met.
Claims
1. A sample work vehicle with temperature control using liquid nitrogen refrigeration, comprising a frame, a compartment arranged on the top of the frame, and a liquid nitrogen recovery tank arranged inside the frame, characterized in that: The carriage comprises a shell opening upward, a cooling box arranged in the shell, an air duct arranged between the cooling box and the side wall of the shell, and a sealing cover (16) arranged on the top of the cooling box; The cooling box is provided with a nitrogen inlet pipe which is connected to the air duct, the nitrogen inlet pipe is provided with a second low-temperature solenoid valve (15), the low-temperature nitrogen outlet of the nitrogen inlet pipe extends to the bottom of the cooling box, and the cooling box is provided with a first temperature sensor (2) and a nitrogen concentration detector (1); The air duct is provided with a nozzle (8) for spraying liquid nitrogen, a temperature regulating mechanism for vaporizing and regulating the temperature of nitrogen, and a wind wheel (14) for circulating the liquid nitrogen in the air duct, a first low-temperature electromagnetic valve (9) is provided on the connecting pipe of the nozzle (8), and the wind wheel (14) is driven by a rotation driving mechanism; The invention also includes a control system, wherein the first cryogenic solenoid valve (9), the second cryogenic solenoid valve (15), the first temperature sensor (2), the second temperature sensor (4), the nitrogen concentration detector (1), the rotary drive mechanism, and the temperature regulating mechanism are all electrically connected to the control system; when the temperature inside the cooling box drops to the temperature set by the first temperature sensor (2), due to the reduction in the required cooling capacity, the control system controls the temperature of the temperature regulating mechanism according to the result of the PID automatic calculation output according to the set temperature point to achieve dynamic thermal balance.
2. The sample working vehicle with temperature control using liquid nitrogen refrigeration according to claim 1, characterized in that: The shell is a double-layer shell, comprising an inner shell and an outer shell, and a vacuum insulation layer is formed between the inner shell and the outer shell.
3. The sample working vehicle with temperature control using liquid nitrogen refrigeration according to claim 2, characterized in that: A pressure relief valve connected to the interior of the air duct is arranged on the outer wall of the shell, and the pressure relief valve is a mechanical pressure relief valve (13).
4. The sample working vehicle with temperature control using liquid nitrogen refrigeration according to claim 3, characterized in that: The rotary drive mechanism is a fan (12), and the fan (12), the first cryogenic solenoid valve (9), the second cryogenic solenoid valve (15) and the mechanical pressure relief valve (13) are located outside the double-layer shell.
5. The sample working vehicle with temperature control using liquid nitrogen refrigeration according to claim 1, characterized in that: A liquid nitrogen recovery device (6) in communication with the interior of the liquid nitrogen recovery tank is arranged in the air duct, and a liquid level sensor (5) electrically connected to the control system is arranged in the air duct.
6. The sample working vehicle with temperature control using liquid nitrogen refrigeration according to claim 1, characterized in that: A plurality of heat-conducting baffles are arranged in a criss-cross pattern inside the cooling box, and the plurality of heat-conducting baffles divide the interior of the cooling box into a plurality of cavities.
7. The sample working vehicle with temperature control using liquid nitrogen refrigeration according to claim 1, characterized in that: The air duct comprises a front air duct, a rear air duct, a left air duct, a right air duct and a bottom air duct which are interconnected, and the wind wheel (14) is arranged in any one of the front air duct, the rear air duct, the left air duct and the right air duct.
8. The sample working vehicle with temperature control using liquid nitrogen refrigeration according to claim 1, characterized in that: The frame is provided with a folding plate (11) which can be turned over by 0-90 degrees.
9. The sample working vehicle with temperature control using liquid nitrogen refrigeration according to claim 5, characterized in that: The liquid nitrogen recovery device (6) comprises a liquid nitrogen recovery port opening upward, the liquid nitrogen recovery port being larger at the top and smaller at the bottom, the bottom small end of the liquid nitrogen recovery port being provided with at least two drainage ports communicating with the inside of the liquid nitrogen recovery port, the liquid nitrogen recovery port being provided with a brass joint capable of sealing the liquid nitrogen recovery port, the top of the brass joint being connected to a glass fiber reinforced plastic connecting rod, the top of the connecting rod passing through the air duct being connected to a hand wheel (3) for driving the liquid nitrogen recovery device (6) to rise and fall.
10. The sample working vehicle with temperature control using liquid nitrogen refrigeration according to claim 5, characterized in that: The temperature regulating mechanism is an electric heater (10).