A method and system for achieving refrigeration by controlling liquid nitrogen output

Abstract

The invention discloses a method and system for achieving refrigeration by controlling liquid nitrogen output. The method and system are provided with a controller, at least one liquid nitrogen tank, at least one liquid nitrogen delivery pipe with a certain length, a one-way valve and a bifurcated pipe are provided at the front section of the liquid nitrogen delivery pipe, a solenoid valve is provided on the bifurcated pipe, and the front end of the bifurcated pipe is an air inlet, which is used to enter air. The end of the liquid nitrogen delivery pipe is connected to a pressure tank, the pressure tank is connected to a micro air pump through an air pipe, and a solenoid valve is provided on the air pipe of the micro air pump connected to the pressure tank. When the micro air pump is used to pump the pressure tank to a certain negative pressure value, the liquid nitrogen in the liquid nitrogen tank is pumped out to the liquid nitrogen delivery pipe. When a certain amount of liquid nitrogen enters, the solenoid valve on the bifurcated pipe is opened to allow air to enter the liquid nitrogen delivery pipe, and the air pushes the liquid nitrogen to flow forward. When a certain amount of air enters, the solenoid valve on the bifurcated pipe is closed, so that a certain amount of liquid nitrogen is pumped out from the liquid nitrogen tank again, thereby repeatedly transporting liquid nitrogen and air flowing in the liquid nitrogen delivery pipe for refrigeration.

Description

Technical Field

[0001] The present invention relates to the field of refrigeration technology, and in particular to a method and system for realizing liquid nitrogen refrigeration by controlling liquid nitrogen output. Background Art

[0002] At present, humans have been using Freon air conditioners to adjust indoor temperature to pursue a comfortable temperature for more than a hundred years. More and more people and some special places cannot do without air conditioners, and the popularity of air conditioners is getting higher and higher, especially in developing countries. However, as a large number of Freon air conditioners are put into the market and enter thousands of households to bring comfort to people, the negative problems they bring are becoming more and more obvious.

[0003] First, the use of a large number of air conditioners around the world contains chemicals that will produce a large number of ozone-depleting substances (ODS). Their emissions cause serious damage to the ozone layer, threatening human health and the healthy operation of the ecosystem. When these substances reach high altitudes, they will react with the oxygen atoms of ozone, continuously destroying the composition of ozone and causing varying degrees of damage to the ozone layer. At the same time, the stratosphere and troposphere of the air are destroyed, causing the earth's temperature to rise. Therefore, humans urgently need to solve the pollution caused by CFCs and develop and utilize alternatives.

[0004] Secondly, traditional air conditioners need to be installed in a fixed position, so the air outlet (indoor unit) cannot be moved, which brings inconvenience to users. At the same time, traditional air conditioners need to cool the entire space, which easily leads to energy waste.

[0005] In addition, there is a kind of air cooler and air conditioning fan on the market, which requires a special ice pot, and the ice pot needs to be frozen in a freezer, which has a poor effect and brings inconvenience to the user. Summary of the invention

[0006] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a method and system for realizing liquid nitrogen refrigeration by controlling the output of liquid nitrogen. The system realizes refrigeration by absorbing a large amount of heat when vaporizing due to the characteristics of liquid nitrogen. It is safe, reliable, zero-pollution and low-power. Nitrogen exists in large quantities in the air, which is harmless and safe to humans (inert gas). At the same time, the technology greatly reduces the power consumption of traditional air conditioners, truly realizing low power consumption and zero-pollution emissions.

[0007] The present technical solution proposes a method for achieving refrigeration by controlling the output of liquid nitrogen, comprising providing at least one liquid nitrogen tank and at least one liquid nitrogen delivery pipe of a certain length, wherein the front end of the liquid nitrogen delivery pipe is inserted into the bottom of the liquid nitrogen tank, the liquid nitrogen tank is filled with liquid nitrogen for standby use, and the liquid nitrogen delivery pipe is provided with a one-way valve and a bifurcated pipe connected to the liquid nitrogen delivery pipe at the tank cover position of the liquid nitrogen tank, the bifurcated pipe is provided with a solenoid valve, and the front end of the bifurcated pipe is an air inlet, which is used to enter air.

[0008] A pressure tank is connected to the end of the liquid nitrogen delivery pipe. The pressure tank is connected to a micro air pump through an air pipe. An electromagnetic valve is arranged on the air pipe connecting the micro air pump to the pressure tank. The micro air pump is used to pump the pressure tank to a certain negative pressure value. The liquid nitrogen in the liquid nitrogen tank is pumped out to the liquid nitrogen delivery pipe. When a certain amount of liquid nitrogen enters, the electromagnetic valve on the bifurcated pipe is opened to allow air to enter the liquid nitrogen delivery pipe. The air pushes the liquid nitrogen to flow forward. When a certain amount of air enters, the electromagnetic valve on the bifurcated pipe is closed, thereby pumping out a certain amount of liquid nitrogen from the liquid nitrogen tank again. Then, the electromagnetic valve on the bifurcated pipe is started again to allow air to enter. Liquid nitrogen is repeatedly transported and air flows in the liquid nitrogen delivery pipe for refrigeration.

[0009] The liquid nitrogen delivery pipe is coiled into at least two groups of cooling pipe groups as cooling pipe groups for refrigeration, wherein the front group is provided with a water tank to place it in water, the rear group is fixed to the upper end of the water tank and is provided with a plurality of cooling fins, a fan is provided on the rear side of the upper cooling pipe group, a water containing plate is provided on the top, and a micro water pump is provided to pump water in the water tank to the water containing plate, and water leaks back to the water tank from the edge of the water containing plate to form water circulation refrigeration.

[0010] The pressure tank is also connected to at least one gas output pipe, which is provided with a pressure relief valve. Liquid nitrogen is transported to the end of the liquid nitrogen delivery pipe and absorbs heat to form atomized cold air. The atomized cold air is ejected from the gas output pipe. The end of the gas output pipe is placed in front of the cooling pipe group above the water tank to form atomized cold air refrigeration.

[0011] At least one controller is provided, and the controller is connected with the electromagnetic valve and the micro air pump, the micro water pump, and is also connected with a temperature sensor, a pressure sensor, a clock unit and an alarm unit.

[0012] A system for achieving refrigeration by controlling liquid nitrogen output based on the above method mainly consists of three parts: a liquid nitrogen output system, a refrigeration system and a control system.

[0013] The liquid nitrogen output system includes at least one liquid nitrogen tank, at least one liquid nitrogen delivery pipe, the front end of the liquid nitrogen delivery pipe is inserted into the bottom of the liquid nitrogen tank, a one-way valve and a bifurcated pipe are arranged at the front end position where the liquid nitrogen delivery pipe leads out the liquid nitrogen in the liquid nitrogen tank, a first solenoid valve is arranged on the bifurcated pipe, the front end of the bifurcated pipe is an air inlet, and an air inlet filter is arranged on the air inlet.

[0014] The refrigeration system includes water circulation refrigeration, cooling pipe group refrigeration and atomized cold air refrigeration.

[0015] The liquid nitrogen delivery pipe is coiled to form a cooling pipe group, the rear end of the liquid nitrogen delivery pipe is connected to a pressure tank, the pressure tank is connected to a micro air pump through a pipeline, the pressure tank is pumped into a negative pressure by the micro air pump, and the liquid nitrogen is led out of the liquid nitrogen tank, the pressure tank is connected to at least one gas output pipe, a pressure relief valve is provided between the gas output pipe and the pressure tank, the gas output pipe outputs atomized cold air to form atomized cold air refrigeration, and an atomizing nozzle is provided at the front end of the gas output pipe.

[0016] The control system includes at least one controller, and the controller is connected to the first solenoid valve, the micro air pump, and the pressure relief valve.

[0017] Furthermore, the cooling pipe group includes a spiral coil group and a U-shaped coil group. A water tank is set to place the spiral coil group in the water in the water tank. The U-shaped coil group is arranged above the water tank. A water receiving plate is set on the U-shaped coil. A micro water pump is set to pump the water in the water tank to the water receiving plate. The water receiving plate is provided with a water inlet hole and a "water channel". The water channel is arranged on the edge of the plate. A number of leakage holes for leaking water downwards are set in the water channel, and the water circulates back to the water tank.

[0018] Furthermore, a plurality of neatly arranged cooling fins are arranged in the U-shaped coil, and a fan is arranged at the rear side of the U-shaped coil.

[0019] Preferably, a water curtain is provided at the bottom of the "water channel" of the water containing plate.

[0020] Preferably, the micro air pump includes a first micro air pump and a second micro air pump, a second solenoid valve is arranged between the first micro air pump and the pressure tank, a third solenoid valve is arranged between the second micro air pump and the pressure tank, and the second solenoid valve and the third solenoid valve are connected to the controller.

[0021] Preferably, the controller is also connected to a temperature sensor, a pressure sensor, a clock unit and an alarm unit.

[0022] This technology has achieved the following by upgrading and innovating the existing fans and cooling fans on the market: 1. Powerful refrigeration, through the superposition of water circulation refrigeration, cooling pipe group and cooling fin refrigeration and atomization refrigeration, the cooling effect is more obvious.

[0023] 2. Safe and reliable, zero pollution and low power consumption. A large amount of nitrogen exists in the air, which is harmless and safe to humans (inert gas). At the same time, this technology greatly reduces the power consumption of traditional air conditioners and truly achieves low power consumption and zero pollution emissions.

[0024] 3. This technology is not limited or affected by volume, and is suitable for indoor and outdoor use. It can be designed as a portable USB fan (minus the water circulation part) according to demand, which can greatly enhance the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1It is a schematic diagram of the liquid nitrogen output, cooling pipe group refrigeration and atomized cold air refrigeration structure of the present invention.

[0026] Figure 2 for Figure 1 Schematic diagram of the back view structure.

[0027] Figure 3 This is a schematic diagram of the water tank and water curtain structure of the present invention.

[0028] Figure 4 for Figure 3 Schematic diagram of removing the front water curtain cloth.

[0029] Figure 5 It is a principle block diagram of the liquid nitrogen output and refrigeration process of the present invention.

[0030] Figure 6 A controller control flow diagram is listed for the present invention. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to further understand the features and technical contents of the present invention, embodiments of the present invention are described in detail below in conjunction with the accompanying drawings and implementation methods.

[0032] The present invention provides a method for achieving refrigeration by controlling liquid nitrogen output, referring to Figure 1-5 The method is provided with a controller, at least one liquid nitrogen tank 1, at least one liquid nitrogen delivery pipe 20 with a certain length, the front end of the liquid nitrogen delivery pipe 20 is inserted into the bottom of the liquid nitrogen tank 1, the liquid nitrogen tank 1 is filled with liquid nitrogen for standby, the liquid nitrogen delivery pipe 20 is provided with a one-way valve 2 and a bifurcated pipe connected to the liquid nitrogen delivery pipe at the tank cover position of the liquid nitrogen tank 1, the bifurcated pipe is provided with a solenoid valve, the front end of the bifurcated pipe is an air inlet 10, and the air inlet is used to enter the air.

[0033] A pressure tank 16 is connected to the end of the liquid nitrogen delivery pipe 20. The pressure tank 16 is connected to a micro air pump through an air pipe. A solenoid valve is arranged on the air pipe connecting the micro air pump to the pressure tank 16. When the micro air pump is used to pump the pressure tank 16 to a certain negative pressure value, the liquid nitrogen in the liquid nitrogen tank 1 is pumped out to the liquid nitrogen delivery pipe 20. When a certain amount of liquid nitrogen enters, the solenoid valve on the bifurcated pipe is opened to allow air to enter the liquid nitrogen delivery pipe 20. The air pushes the liquid nitrogen to flow forward. When a certain amount of air enters, the solenoid valve on the bifurcated pipe is closed, thereby pumping out a certain amount of liquid nitrogen from the liquid nitrogen tank 1 again, and then the solenoid valve on the bifurcated pipe is started again to allow air to enter, thereby repeatedly transporting liquid nitrogen and air flowing in the liquid nitrogen delivery pipe 20 for refrigeration.

[0034] The liquid nitrogen delivery pipe 20 is coiled into at least two groups of cooling pipe groups as cooling pipe group refrigeration, wherein the front end group is provided with a water tank 5 to place it in water, the end group is fixed to the upper end of the water tank 5 and is provided with a plurality of cooling fins 2021, and a fan is provided on the rear side of the upper cooling pipe group, a water containing plate 30 is provided on the top, and a micro water pump is provided to pump the water in the water tank 5 to the water containing plate 30, and the water leaks back to the water tank 5 from the edge of the water containing plate 30 to form water circulation refrigeration.

[0035] The pressure tank 1 is also connected to at least one gas output pipe 14, on which a pressure relief valve 9 is provided. Liquid nitrogen is transported to the end of the liquid nitrogen delivery pipe 14 and absorbs heat to form atomized cold air, which is ejected from the gas output pipe 14. The end of the gas output pipe 14 is arranged in front of the cooling pipe group above the water tank 5 to form atomized cold air refrigeration.

[0036] At least one controller is provided, and the controller is connected with the electromagnetic valve and the micro air pump, the micro water pump, and is also connected with a temperature sensor, a pressure sensor, a clock unit and an alarm unit.

[0037] Please refer to the attached Figure 1-4 A system for achieving refrigeration by controlling liquid nitrogen output, the system mainly consists of three parts: a liquid nitrogen output system, a refrigeration system and a control system. The liquid nitrogen output system includes at least one liquid nitrogen tank 1, at least one liquid nitrogen delivery pipe 20, the front end of the liquid nitrogen delivery pipe 20 is inserted into the bottom of the liquid nitrogen tank 1, a one-way valve 2 and a bifurcated pipe are arranged at the front end position of the liquid nitrogen delivery pipe 20 leading out the liquid nitrogen in the liquid nitrogen tank 1, a first solenoid valve 6 is arranged on the bifurcated pipe, the front end of the bifurcated pipe is an air inlet 10, and an air inlet filter element is arranged on the air inlet 10.

[0038] The refrigeration system includes water circulation refrigeration, cooling pipe group refrigeration and atomized cold air refrigeration.

[0039] The liquid nitrogen delivery pipe 20 is coiled to form a cooling pipe group, and the rear end of the liquid nitrogen delivery pipe 20 is connected to a pressure tank 16. The pressure tank 16 is connected to a micro air pump through a pipeline. The pressure tank 16 is pumped into a negative pressure by the micro air pump to realize the liquid nitrogen being drawn out from the liquid nitrogen tank 1. The pressure tank 16 is connected to at least one gas output pipe 14. A pressure relief valve 9 is provided between the gas output pipe 14 and the pressure tank 16. The gas output pipe 14 outputs atomized cold air to form atomized cold air refrigeration. An atomizing nozzle 15 is provided at the front end of the gas output pipe 14.

[0040] The control system includes at least one controller, which is connected to the first solenoid valve 6 , the micro air pump, and the pressure relief valve 9 .

[0041] As one of the preferred schemes, the cooling pipe group includes a spiral coil group 201 and a U-shaped coil group 202. A water tank 5 is set to place the spiral coil group 201 in the water in the water tank 5. The U-shaped coil group 202 is arranged above the water tank 5. A water receiving plate 30 is set on the U-shaped coil group 202. A micro water pump is set to pump the water in the water tank 5 to the water receiving plate 30. The water receiving plate 30 is provided with a water inlet hole 301 and a "water channel" 302. The "water channel" 302 is arranged at the edge of the plate. A number of water leakage holes 303 for leaking water downwards are set in the "water channel" 302. The water circulates back to the water tank 5 to form water circulation refrigeration.

[0042] Preferably, a plurality of neatly arranged cooling fins 2021 are disposed in the U-shaped coil unit 202, and a fan 11 is disposed at the rear side of the U-shaped coil unit 202, and the fan 11 is connected to a controller.

[0043] Preferably, a water curtain 31 is provided at the bottom of the “water channel” 302 of the water containing plate 30 .

[0044] Preferably, the micro air pump includes a first micro air pump 3 and a second micro air pump 4, a second solenoid valve 7 is arranged between the first micro air pump 3 and the pressure tank 16, a third solenoid valve 8 is arranged between the second micro air pump 4 and the pressure tank 16, and the second solenoid valve 7 and the third solenoid valve 8 are connected to the controller.

[0045] Preferably, the controller is also connected to a temperature sensor, a pressure sensor, a clock unit and an alarm unit.

[0046] Please refer to Figure 1-5 ,in Figure 5It is a principle block diagram of the liquid nitrogen output and refrigeration process of the present technical solution. The controller controls the start of the first micro air pump 3 and the second solenoid valve 7 to pump the pressure tank 16 into a negative pressure. When the negative pressure value reaches a certain value, the liquid nitrogen in the liquid nitrogen tank 1 is pumped out from the liquid nitrogen tank 1. When a certain amount of liquid nitrogen is pumped out, the first solenoid valve 6 is started to allow air to enter the liquid nitrogen delivery pipe 20 from the bifurcated pipe. When the liquid nitrogen is transported to a certain position of the liquid nitrogen delivery pipe 20, the first solenoid valve 6 is closed again, thereby pumping out a certain amount of liquid nitrogen, and then the first solenoid valve 6 is started again to allow air to enter, and this is repeated. Thus, the pipes of the spiral coil group 201 and the U-shaped coil group 202 are distributed in a section of air and a section of liquid nitrogen. The liquid nitrogen absorbs a certain amount of heat in the spiral coil group 201, so that the water in the water tank 5 becomes chilled water, so that the chilled water is pumped from the water tank 5 to the water holding plate 30 above, and then leaks from the water leakage hole 303 of the "water channel" 302 to form a cold water curtain, and the water curtain cloth 31 allows the cold water to stay on it longer. The cooling fins 2021 arranged on the U-shaped coil group 202 allow the liquid nitrogen in the U-shaped coil group 202 to absorb the heat on the cooling fins 2021, so that the U-shaped coil group 202 and the cooling fins 2021 are cooled, so that the fan 11 blows air from the back side, which can blow low-temperature cold air to the external environment, so that the ambient temperature is reduced. At this time, the liquid nitrogen that continues to be transported forward from the U-shaped coil group 202 gradually becomes atomized nitrogen and air. The atomized nitrogen and air are also at a lower temperature. The atomized nitrogen is transported to the pressure tank 16, the first micro air pump 3 stops, and the second micro air pump 4 and the third solenoid valve 8 are started to pressurize the pressure tank 16. When the pressure tank 16 is pressurized to a certain value, the pressure relief valve 9 is opened, so that the atomized nitrogen and air are ejected from the atomizing nozzle 15, so that the fan 11 outputs cold air with the triple superposition of water circulation refrigeration, cooling pipe group refrigeration and atomized cold air refrigeration, thereby achieving efficient refrigeration.

[0047] Please refer to Figure 6 The control system of the present technical solution may include automatic control and manual control modes. The temperature monitored by the temperature sensor is compared with the temperature value set by the built-in code, so as to automatically control the output of "high, medium, and low" gears. In manual mode, the "high, medium, and low" gears can be controlled by buttons. Each gear is set by the time of extracting liquid nitrogen. The longer the extraction time, the more liquid nitrogen is extracted. The more liquid nitrogen, the lower the refrigeration temperature. At the same time, the output liquid nitrogen can be set to pause at a certain position, and the air input is controlled by the first solenoid valve 6. The air input pushes the liquid nitrogen forward. The refrigeration temperature can also be controlled by controlling the time of liquid nitrogen pause.

[0048] The above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. However, obvious changes or modifications derived from the essence of the present invention still fall within the protection scope of the present invention.

Claims

1. A system for achieving refrigeration by controlling liquid nitrogen output, characterized in that: The system mainly consists of three parts: liquid nitrogen output system, refrigeration system and control system; The liquid nitrogen output system comprises at least one liquid nitrogen tank (1), at least one liquid nitrogen delivery pipe (20), the front end of the liquid nitrogen delivery pipe (20) being inserted into the bottom of the liquid nitrogen tank (1), a one-way valve (2) being arranged at the front end of the liquid nitrogen delivery pipe (20) leading out the liquid nitrogen in the liquid nitrogen tank (1), and a bifurcated pipe, a first solenoid valve (6) being arranged on the bifurcated pipe, and the front end of the bifurcated pipe being an air inlet (10); The refrigeration system includes water circulation refrigeration, cooling pipe group refrigeration and atomized cold air refrigeration; The liquid nitrogen delivery pipe (20) is wound to form a cooling pipe group. The rear end of the liquid nitrogen delivery pipe (20) is connected to a pressure tank (16). The pressure tank (16) is connected to a micro air pump through a pipeline. The pressure tank (16) is pumped into a negative pressure by the micro air pump to achieve the purpose of leading the liquid nitrogen from the liquid nitrogen tank (1). The pressure tank (16) is connected to at least one gas output pipe (14). A pressure relief valve (9) is provided between the gas output pipe (14) and the pressure tank (16). The gas output pipe (14) outputs atomized cold air to form atomized cold air refrigeration. The control system comprises at least one controller, and the controller is connected to a first solenoid valve (6), a micro air pump, and a pressure relief valve (9); The cooling pipe group comprises a spiral coil group (201) and a U-shaped coil group (202); a water tank (5) is provided to place the spiral coil group (201) in water in the water tank (5); the U-shaped coil group (202) is arranged above the water tank (5); a water receiving plate (30) is provided on the U-shaped coil group (202); a micro water pump is provided to pump water in the water tank (5) to the water receiving plate (30); a water inlet hole (301) and a "water channel" (302) are provided on the water receiving plate (30); the "water channel" (302) is arranged at the edge of the plate; a plurality of water leakage holes (303) for leaking water downward are provided in the "water channel" (302); water circulates back to the water tank (5) to form water circulation refrigeration; A plurality of neatly arranged cooling fins (2021) are arranged in the U-shaped coil group (202), a fan (11) is arranged on the rear side of the U-shaped coil group (202), and the fan (11) is connected to a controller; A water curtain (31) is provided at the bottom of the "water channel" (302) of the water holding plate (30); The micro air pump comprises a first micro air pump (3) and a second micro air pump (4); a second solenoid valve (7) is arranged between the first micro air pump (3) and the pressure tank (16); a third solenoid valve (8) is arranged between the second micro air pump (4) and the pressure tank (16); the second solenoid valve (7) and the third solenoid valve (8) are connected to a controller.

2. A system for achieving refrigeration by controlling liquid nitrogen output according to claim 1, characterized in that: The controller is also connected to a temperature sensor, a pressure sensor, a clock unit and an alarm unit.

3. A system for achieving refrigeration by controlling liquid nitrogen output according to claim 1, characterized in that: An air intake filter is provided on the air intake port (10).

4. A system for achieving refrigeration by controlling liquid nitrogen output according to claim 1, characterized in that: The front end of the gas output pipe (14) is provided with an atomizing nozzle (15).

5. A method for achieving refrigeration by controlling liquid nitrogen output, which uses the system for achieving refrigeration by controlling liquid nitrogen output as claimed in any one of claims 1 to 4, characterized in that: At least one liquid nitrogen tank (1) and at least one liquid nitrogen delivery pipe (20) of a certain length are provided, the front end of the liquid nitrogen delivery pipe (20) is inserted into the bottom of the liquid nitrogen tank (1), the liquid nitrogen tank (1) is filled with liquid nitrogen for standby use, a one-way valve (2) connected to the liquid nitrogen delivery pipe and a bifurcated pipe are provided on the liquid nitrogen delivery pipe (20) at the tank cover position of the liquid nitrogen tank (1), a solenoid valve is provided on the bifurcated pipe, and the front end of the bifurcated pipe is an air inlet (10), and the air inlet is used to take in air; A pressure tank (16) is connected to the end of the liquid nitrogen delivery pipe (20). The pressure tank (16) is connected to a micro air pump via an air pipe. An electromagnetic valve is arranged on the air pipe connecting the micro air pump to the pressure tank (16). The micro air pump is used to pump the pressure tank (16) to a certain negative pressure value, and the liquid nitrogen in the liquid nitrogen tank (1) is pumped out to the liquid nitrogen delivery pipe (20). When a certain amount of liquid nitrogen enters, the electromagnetic valve on the bifurcated pipe is opened to allow air to enter the liquid nitrogen delivery pipe (20). The air pushes the liquid nitrogen to flow forward. When a certain amount of air enters, the electromagnetic valve on the bifurcated pipe is closed, thereby pumping out a certain amount of liquid nitrogen from the liquid nitrogen tank (1). Then, the electromagnetic valve on the bifurcated pipe is started again to allow air to enter. Thus, liquid nitrogen is repeatedly transported and air flows in the liquid nitrogen delivery pipe (20) for refrigeration. The liquid nitrogen delivery pipe (20) is coiled into at least two groups of cooling pipe groups as cooling pipe group refrigeration, wherein the front group is provided with a water tank (5) and placed in water, the rear group is fixed to the upper end of the water tank (5) and provided with a plurality of cooling fins (2021), a fan is provided on the rear side of the upper cooling pipe group, a water containing plate (30) is provided on the top, a micro water pump is provided to pump water in the water tank (5) onto the water containing plate (30), and water leaks back to the water tank (5) from the edge of the water containing plate (30) to form water circulation refrigeration; The pressure tank (16) is also connected to at least one gas output pipe (14), and a pressure relief valve (9) is arranged on the gas output pipe (14). Liquid nitrogen is transported to the end of the liquid nitrogen transport pipe (20) and forms atomized cold air due to heat absorption. The atomized cold air is ejected from the gas output pipe (14). The end of the gas output pipe (14) is arranged in front of the cooling pipe group above the water tank (5), thereby forming atomized cold air refrigeration. At least one controller is provided, and the controller is connected with the electromagnetic valve and the micro air pump, the micro water pump, and is also connected with a temperature sensor, a pressure sensor, a clock unit and an alarm unit.

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