Gas-liquid two-phase cooling and lubricating system based on low-temperature carbon dioxide recycling and working method of gas-liquid two-phase cooling and lubricating system

Abstract

The invention provides a gas-liquid two-phase cooling and lubricating system based on low-temperature carbon dioxide recycling and a working method thereof. The device mainly comprises a cutting fluid supply part, a carbon dioxide supply part, a mixing nozzle device, a cutting unit, a collecting unit and an analyzing unit, the cutting fluid supply part is composed of a cutting fluid storage unit, a conveying pump and a first adjusting device. The carbon dioxide supply part is composed of a buffer tank, a liquefier, a liquid carbon dioxide bottle, a pressure reduction and flow stabilization device and a second adjusting device. The analysis unit consists of a cutting fluid rich liquid inlet, a reaction device, a condenser, a gaseous carbon dioxide outlet, a reboiler and a cutting fluid barren liquid outlet; the cutting fluid supply part and the carbon dioxide supply part input cutting fluid and carbon dioxide into the mixing nozzle device correspondingly, the carbon dioxide is subjected to phase change in the mixing nozzle device and mixed with the cutting fluid, a low-temperature gas-liquid mixture is formed, a cutting area is efficiently cooled, the temperature in the cutting process can be remarkably reduced, and the cutting efficiency is improved. Carbon dioxide in the rich liquid of the cutting fluid is analyzed through the analysis unit, so that recycling of the carbon dioxide is realized, and a green sustainable manufacturing concept is met.

Description

Technical Field

[0001] The invention belongs to the technical field of low-temperature cooling for cutting processing, and in particular relates to a gas-liquid two-phase cooling and lubrication system based on the circulation of low-temperature carbon dioxide and a working method thereof. Technical Background

[0002] During the cutting process of the machine tool, a complex force-heat coupling is formed between the tool, the chip and the workpiece. The tool, known as the "teeth" of the machine tool, often suffers from damage in the form of wear, chipping and bonding under the action of force-heat coupling, which in turn causes surface defects of the workpiece. In addition, due to the occurrence of tool wear, chipping and bonding, the tool life is reduced. Therefore, a good cooling method is needed to ensure the processing quality and increase the tool life.

[0003] Cryogenic gas cooling is a method of sending cryogenic liquid nitrogen and cryogenic liquid carbon dioxide as cooling media into the cutting unit for cooling. The lowest temperatures of liquid nitrogen and liquid carbon dioxide can reach -196° and -76° respectively. Compared with the traditional cooling method using cutting fluid, cryogenic gas cooling processing can achieve lower cutting temperatures. However, due to the economic efficiency of liquid nitrogen, liquid nitrogen cooling is rarely used in actual processing. The disadvantage of cryogenic liquid carbon dioxide is that the carbon dioxide waste gas after gasification and heat absorption is directly discharged into the atmosphere, which does not conform to the basic concept of green manufacturing and sustainable manufacturing. Therefore, a new cutting auxiliary cooling system is urgently needed to ensure the controllable recycling of carbon dioxide gas after gasification and heat absorption. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art, thereby providing a gas-liquid two-phase cooling lubrication system based on the circulation of low-temperature carbon dioxide and a working method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme:

[0006] A gas-liquid two-phase cooling lubrication system based on the circulation of low-temperature carbon dioxide comprises a cutting fluid supply part, a carbon dioxide supply part, a mixing nozzle device, a cutting unit, a collecting unit and an analyzing unit.

[0007] The cutting fluid supply part is mainly composed of a cutting fluid storage unit, a delivery pump and a first regulating device. The cutting fluid is stored in the cutting fluid storage unit. The cutting fluid is sprayed from the mixing nozzle device to the cutting unit through the delivery pump. The first regulating device can adjust the flow rate of the cutting fluid. The cutting fluid collection unit re-collects the cutting fluid to realize the recycling of the cutting fluid.

[0008] The first regulating device regulates the cutting fluid output flow rate range to 5-20L / min.

[0009] The carbon dioxide supply part is mainly composed of a buffer tank, a liquefier, a booster pump, a liquid carbon dioxide bottle, a pressure reducing and stabilizing flow device and a second regulating device. The carbon dioxide is stored in the liquid carbon dioxide bottle in a liquid state under normal conditions. The pressure reducing and stabilizing flow device is used to keep the outlet pressure and flow stable, thereby reducing the fluctuation of the output pressure and flow. When the liquid carbon dioxide passes through the mixing nozzle device, due to the drastic change in pressure, the liquid carbon dioxide is rapidly vaporized and absorbs the heat of the surrounding environment. The low-temperature carbon dioxide gas is mixed with the cutting fluid in the mixing nozzle device to form a low-temperature gas-liquid mixture, which is ejected in a directional manner through the nozzle outlet.

[0010] The second regulating device finely adjusts the mass flow rate of liquid carbon dioxide entering the mixing nozzle device to ensure that the output of liquid carbon dioxide can be accurately regulated. The ratio of the output mass flow rate of liquid carbon dioxide to the output mass flow rate of cutting fluid is 1:300.

[0011] The mixing nozzle device is composed of a first cutting fluid inlet, a mixing ratio regulating valve body, a carbon dioxide inlet, a mixing ratio regulating locking screw, a first fixing pin, a second fixing pin, a mixing chamber sealing ring, a second cutting fluid inlet, a mixing chamber, and a nozzle. The carbon dioxide inlet is placed on the top of the mixing ratio regulating valve body, and is used to deliver the low-temperature carbon dioxide gas-liquid mixture into the mixing chamber. The first cutting fluid inlet and the second cutting fluid inlet are placed on both sides of the mixing nozzle device, and are used to deliver the cutting fluid into the mixing chamber. The mixing chamber is responsible for mixing the low-temperature carbon dioxide gas and the cutting fluid to form a low-temperature gas-liquid mixture containing carbon dioxide. The nozzle is placed at the bottom of the mixing nozzle device, and plays a role in directional spraying of the low-temperature cutting fluid.

[0012] The cutting fluid is prepared by adding 1.5% of organic amine to oil-based cutting fluid or adding 30wt.% of organic amine and 35wt.% of ethylene glycol to ordinary water-based cutting fluid before dilution. The organic amine absorbs and captures carbon dioxide, and the ethylene glycol increases the freezing point of the cutting fluid. The organic amine can be any one of primary amine (MEA), secondary amine (DEA), tertiary amine (MDEA) and sterically hindered amine (AMP) or a mixture of several of them.

[0013] Further, the overall reaction equation of primary amine and secondary amine with carbon dioxide is: Each mol of primary or secondary amine can absorb 0.5 mol of carbon dioxide; the overall reaction equation of tertiary amine and carbon dioxide is: Each mole of tertiary amine can absorb 1 mol of carbon dioxide; the overall reaction equation of sterically hindered amine and carbon dioxide is: Each mole of tertiary amine can absorb 1 mol of carbon dioxide.

[0014] The analysis unit is composed of a cutting fluid rich liquid inlet, a cutting fluid lean liquid outlet, a gaseous carbon dioxide outlet, a condenser, a reaction device and a reboiler. The cutting fluid rich liquid inlet is connected to the outlet of the collection unit, the carbon dioxide outlet is connected to the inlet of the buffer tank, and the cutting fluid lean liquid outlet is connected to the inlet of the cutting fluid storage unit. The cutting fluid rich liquid flows into the reaction device from the collection unit, and the reboiler heats the carbon dioxide gas to re-analyze the cutting fluid rich liquid. The carbon dioxide gas enters the buffer tank through the gaseous carbon dioxide outlet, and the obtained cutting fluid lean liquid re-enters the cutting fluid storage unit through the cutting fluid lean liquid outlet.

[0015] The mixing chamber is composed of a cutting fluid annular nozzle, a carbon dioxide mixing nozzle, a first cutting fluid circulation wall, and a second cutting fluid circulation wall. The diameter of the cutting fluid annular nozzle is 3-4 mm larger than the diameter of the carbon dioxide mixing nozzle. The cross-sectional curve shape of the first cutting fluid circulation wall is an ellipsoid with a length-to-diameter ratio of 0.7, and the cross-sectional curve shape of the second cutting fluid circulation wall is an ellipsoid with a length-to-diameter ratio of 0.5. The mixing ratio adjustment distance between the first cutting fluid circulation wall and the second cutting fluid circulation wall is adjusted by rotating the mixing ratio adjustment valve body. When the cutting fluid viscosity is less than 2 mPa·s, the mixing ratio adjustment distance is adjusted between 0.5-2 mm. When the cutting fluid viscosity is greater than 2 mPa·s, the mixing ratio adjustment distance is adjusted between 2-3.5 mm. The controllable adjustment of the diffusion radius of the jet of cutting fluids with different viscosities can be achieved to ensure the mixing uniformity of cutting fluids with different viscosities and the low-temperature carbon dioxide gas-liquid mixture.

[0016] The rotating adjustment thread on the outside of the mixing ratio regulating valve body cooperates with the internal thread on the mixing nozzle device, and the mixing ratio regulating valve body is rotated to achieve fine adjustment of the mixing ratio of the low-temperature carbon dioxide gas-liquid mixture and the cutting fluid. The mixing ratio regulating locking screw is installed on the mixing ratio regulating valve body through a thread, and the first locking pin is tightened by rotating the mixing ratio regulating locking screw, and the fixing of the mixing ratio regulating valve body is achieved by the inclined surface cooperation of the first locking pin and the second locking pin.

[0017] After the cutting fluid and the low-temperature carbon dioxide gas-liquid mixture are fully mixed, they are directionally transported to the cutting area through a nozzle, are affected by the cutting heat, and reach the reaction temperature of the organic amine in the cutting fluid absorbing carbon dioxide. The organic amine in the cutting fluid begins to absorb the vaporized carbon dioxide gas, and the cutting fluid rich liquid formed enters the cutting fluid collection unit.

[0018] The present invention also provides a working method of a gas-liquid two-phase cooling lubrication system based on the circulation of low-temperature carbon dioxide, and the specific steps are as follows:

[0019] Step 1: Turn on the cutting fluid delivery pump, and the cutting fluid cools the cutting unit through the mixing nozzle device;

[0020] Step 2: Open the valve of the liquid carbon dioxide bottle, the pressure of the liquid carbon dioxide drops sharply and it gasifies quickly. The low-temperature carbon dioxide gas enters the mixing nozzle device and mixes with the cutting fluid to form a low-temperature gas-liquid mixture, which enhances the cooling effect on the cutting unit.

[0021] Step 3: The low-temperature gas-liquid mixture is subjected to the cutting heat of the cutting unit. When the temperature of the gas-liquid mixture reaches the reaction temperature of the organic amine capturing the carbon dioxide gas, the organic amine in the liquid begins to capture the carbon dioxide gas and generates carbamate or bicarbonate soluble in water;

[0022] Step 4: After capturing carbon dioxide gas, the rich cutting fluid passes through the collection unit and enters the analysis unit for secondary reaction to analyze carbon dioxide gas again;

[0023] Step 5: The lean cutting fluid after analysis flows back into the cutting fluid storage unit to realize the recycling of cutting fluid;

[0024] Step 6: The analyzed carbon dioxide gas returns to the buffer tank again, and is re-pressurized into liquid carbon dioxide through a liquefier to achieve the recycling of carbon dioxide.

[0025] Compared with the prior art, the advantages of the gas-liquid two-phase cooling lubrication system based on the circulation of low-temperature carbon dioxide and the working method thereof provided by the present invention are as follows:

[0026] 1. Utilizing the absorption and decomposition reaction characteristics of organic amines and carbon dioxide, when the cutting unit is in the cooling stage, the cutting fluid is subjected to the cutting heat to reach the reaction temperature of the organic amine, the organic amine absorbs carbon dioxide, and then decomposes the carbon dioxide gas in the decomposition stage, recycling carbon dioxide, reducing carbon dioxide emissions and achieving low-carbon and environmentally friendly processing.

[0027] 2. Liquid carbon dioxide vaporizes and absorbs heat, which rapidly reduces the temperature of the cutting fluid. The vaporized gas-liquid mixture is integrated into the cutting fluid through a mixing nozzle. When the pressure is reduced when entering the cutting unit and it is subjected to cutting heat, the remaining gas-liquid mixture further vaporizes and absorbs heat, achieving continuous low-temperature cooling processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a gas-liquid two-phase cooling and lubrication system based on low-temperature carbon dioxide circulation in the present invention;

[0029] Figure 2 It is a schematic diagram of the mixing nozzle device in the present invention;

[0030] Figure 3 It is an axonometric view of the mixing nozzle device of the present invention;

[0031] Figure 4 This is a partial enlarged view of location Ⅰ;

[0032] Figure 5 This is a partial enlarged view of location II;

[0033] Figure 6 It is a schematic diagram of the collection unit in the present invention;

[0034] Figure 7 It is a schematic diagram of the analysis unit in the present invention;

[0035] Figure 8 The present invention is a flow chart of a working method of a gas-liquid two-phase cooling and lubrication system based on the circulation of low-temperature carbon dioxide.

[0036] The numbers in the figure are as follows:

[0037] 1. Cutting fluid supply part; 1-1. Cutting fluid storage unit; 1-2. Delivery pump; 1-3. First regulating device; 2. Carbon dioxide supply part; 2-1. Buffer tank; 2-2. Liquefier; 2-3. Booster pump; 2-4. Liquid carbon dioxide bottle; 2-5. Pressure reducing and stabilizing device; 2-6. Second regulating device; 3. Mixing nozzle device; 3-1. First cutting fluid inlet; 3-2. Mixing ratio regulating valve body; 3-2-1. First cutting fluid flow wall; 3-3. Carbon dioxide inlet; 3-4. Mixing ratio locking screw; 3-5. First fixing pin; 3-6. Second fixing pin; 3-7. Mixing chamber seal circle; 3-8. Second cutting fluid inlet; 3-9. Mixing chamber; 3-9-1. Second cutting fluid flow wall; 3-10. Nozzle; 4. Cutting unit; 5. Collecting unit; 5-1. Cutting fluid collecting port; 5-2. Storage tank; 5-3. Pump; 6. Analysis unit; 6-1. Cutting fluid rich liquid inlet; 6-2. Reaction device; 6-3. Condenser; 6-4. Gaseous carbon dioxide outlet; 6-5. Reboiler; 6-6. Cutting fluid lean liquid outlet; 1-A. Rotary adjustment thread; 1-B. Internal thread; 1-C. Carbon dioxide mixing nozzle diameter; 1-D. Cutting fluid annular nozzle diameter; 1-E. Mixing ratio adjustment distance. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only embodiments of a part 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.

[0039] like Figure 1As shown, this embodiment provides a schematic diagram of a gas-liquid two-phase cooling lubrication system based on the circulation of low-temperature carbon dioxide in the present invention, including a cutting fluid supply part 1, a carbon dioxide supply part 2, a mixing nozzle device 3, a cutting unit 4, a collection unit 5 and an analysis unit 6.

[0040] The cutting fluid supply part is mainly composed of a cutting fluid storage unit 1-1, a delivery pump 1-2 and a first regulating device 1-3. The cutting fluid is stored in the cutting fluid storage unit 1-1 under normal conditions. When cooling is required, the cutting fluid is sent to the mixing nozzle device 3 through the delivery pump 1-2. The first regulating device 1-3 is responsible for adjusting the flow rate of the cutting fluid. The range of the cutting fluid flow rate is adjusted to 5-20L / min. The working fluid that has completed cooling flows to the analysis unit 5 through the collection unit 4.

[0041] The carbon dioxide supply part is mainly composed of a buffer tank 2-1, a liquefier 2-2, a booster pump 2-3, a liquid carbon dioxide bottle 2-4, a pressure reducing and stabilizing flow device 2-5 and a second regulating device 2-6. Carbon dioxide is stored in a liquid state in a liquid nitrogen dioxide unit 2-4 under normal conditions. When cooling is required, the valve of the liquid carbon dioxide bottle is opened, and the liquid carbon dioxide flows through the pressure reducing and stabilizing flow device 2-5, and the output pressure of the carbon dioxide is adjusted by the pressure reducing and stabilizing flow device 2-5. The second regulating device 2-6 makes fine adjustments to the flow rate of liquid carbon dioxide entering the mixing nozzle device 3, and can accurately control the output of liquid carbon dioxide. The ratio of the output mass flow rate of liquid carbon dioxide to the output mass flow rate of cutting fluid is 1:300. Since the pressure of carbon dioxide drops sharply when passing through the mixing nozzle device 3, it quickly absorbs the heat of the surrounding environment and undergoes a phase change. The liquid carbon dioxide quickly vaporizes to form low-temperature carbon dioxide gas, which is then introduced into the mixing chamber 3-9 of the mixing nozzle device 3. The carbon dioxide gas is fully in contact with the cutting fluid, and the temperature of the cutting fluid is effectively reduced and the heat exchange efficiency of the cutting fluid is increased through the full fusion and diffusion of the gas-liquid two-phase substances. In addition, the integration of carbon dioxide gas also has a positive effect on the fluidity and permeability of the cutting fluid.

[0042] When the low-temperature gas-liquid mixture is subjected to cutting heat in the cutting unit 4, the organic amine in the cutting fluid begins to capture and absorb carbon dioxide gas molecules. The cutting fluid rich liquid that absorbs carbon dioxide gas molecules enters the analysis unit 5, and the carbon dioxide gas is re-analyzed by the analysis unit 5 and stored in the buffer tank 2-1. It is then re-formed into liquid carbon dioxide through the liquefier 2-2 and further pressurized by the booster pump 2-3 to ensure that it can enter the liquid carbon dioxide bottle 2-4 at a suitable pressure to achieve recycling.

[0043] like Figure 2 , 3As shown, this embodiment provides a mixing nozzle device 3, and low-temperature carbon dioxide gas is injected into the mixing chamber 3-9 through the carbon dioxide inlet 3-3. The cutting fluid is injected into the mixing chamber 3-9 through the first cutting fluid inlet 3-1 and the second cutting fluid inlet 3-8, and the low-temperature carbon dioxide gas is quickly mixed with the cutting fluid in the mixing chamber 3-9. After the low-temperature carbon dioxide gas and the cutting fluid are fully mixed, the temperature of the cutting fluid in the mixing chamber 3-9 can be reduced, which plays a role in assisting the cooling of the cutting fluid. The mixed cutting fluid is sprayed out through the nozzle 3-10, which plays a role in cooling the cutting unit 4. When the cutting fluid is subjected to the cutting heat of the cutting unit 4 and reaches the reaction temperature of the organic amine and the carbon dioxide gas in the cutting fluid, the organic amine absorbs and captures the carbon dioxide gas to form a carbamate or bicarbonate that can be soluble in water, thereby achieving the role of capturing carbon dioxide and preventing carbon dioxide from being directly discharged into the atmosphere.

[0044] like Figure 4 , 5 As shown, the diameter 1-D of the cutting fluid annular nozzle is 3-4 mm larger than the diameter 1-C of the carbon dioxide mixing nozzle. When the cutting fluid flows through the first cutting fluid circulation wall 3-2-1 and the second cutting fluid circulation wall 3-9-1, the cutting fluid has a wall-adhering effect, which causes the cutting fluid to generate a pressure gradient along the radial direction of the mixing chamber 3-9 during the flow process. Since the cutting fluid and the first cutting fluid circulation wall 3-2-1 and the second cutting fluid circulation wall 3-9-1 generate a certain friction resistance and viscosity, the closer the cutting fluid is to the first cutting fluid circulation wall 3-2-1 and the second cutting fluid circulation wall 3-9-1, the slower the cutting fluid flow rate is. The pressure near the middle position of the mixing chamber 3-9 is slightly greater than the pressure at the first cutting fluid circulation wall 3-2-1 and the second cutting fluid circulation wall 3-9-1, which causes the cutting fluid to have a jet diffusion effect when it flows through the cutting fluid annular nozzle. As the jet diffusion effect continues to occur, the flow state of the cutting fluid gradually changes to a dissipated state, thereby accelerating the mixing of the low-temperature carbon dioxide gas and the cutting fluid.

[0045] When the viscosity of the cutting fluid is less than 2mPa·s, the mixing uniformity of the cutting fluid and the low-temperature carbon dioxide gas-liquid mixture can be improved by a high-efficiency mixing nozzle device. First, rotate the mixing ratio locking screw 3-4 counterclockwise to loosen the first fixing pin 3-5 and the second fixing pin 3-6, and then adjust the mixing ratio regulating valve body 3-2 clockwise to reduce the relative distance between the first cutting fluid flow wall 3-2-1 and the second cutting fluid flow wall 3-9-1, thereby increasing the jet diffusion effect when the cutting fluid flows through the cutting fluid annular nozzle. When the adjustment is in place, rotate the mixing ratio locking screw 3-4 clockwise again to tighten the first fixing pin 3-5, and through the inclined surface cooperation of the first fixing pin 3-5 and the second fixing pin 3-6, fix the mixing ratio regulating valve body 3-2 to prevent it from moving. When the viscosity of the cutting fluid is less than 2 mPa·s, the mixing ratio adjustment distance 1-E is adjusted between 0.5-2 mm. When the viscosity of the cutting fluid is greater than 2 mPa·s, the mixing ratio adjustment distance 1-E is adjusted between 2-3.5 mm to ensure the mixing uniformity of cutting fluids with different viscosities and the low-temperature carbon dioxide gas-liquid mixture.

[0046] like Figure 6 As shown, this embodiment provides a schematic diagram of the collection unit 5 in the present invention. The collection unit 5 is composed of a cutting fluid collection port 5-1, a storage tank 5-2 and a pump 5-3. The cutting fluid collection port 5-1 is arranged above the storage tank 5-2. The cooling cutting fluid enters the storage tank 5-2 through the cutting fluid collection port 5-1. The storage tank 5-2 is also equipped with a pump 5-3. The function of the pump 5-3 is to send the rich cutting fluid in the storage tank 5-2 to the analysis unit 6.

[0047] like Figure 7As shown, this embodiment provides a schematic diagram of the analysis unit 6 in the present invention. The analysis unit 6 is composed of a cutting fluid rich liquid inlet 6-1, a cutting fluid lean liquid outlet 6-6, a gaseous carbon dioxide outlet 6-4, a condenser 6-3, a reaction device 6-2 and a reboiler 6-5. The cutting fluid rich liquid contains carbamate or bicarbonate generated by reaction with carbon dioxide. The cutting fluid rich liquid flows steadily into the reaction device 6-2 from the collection unit 5, enters the reaction device 6-2 from the cutting fluid rich liquid inlet 6-1, and accurately controls the heating process through the reboiler 6-5, so that the carbon dioxide gas in the cutting fluid is gradually released and analyzed. Under the precise heating of the reboiler 6-5, the cutting fluid rich liquid is re-analyzed and releases carbon dioxide. The reboiler 6-5 can accurately control the collection efficiency of carbon dioxide. These gaseous carbon dioxides then enter the buffer tank 6-5 through the gaseous carbon dioxide outlet 6-4 for further processing or utilization. At the same time, with the precipitation of carbon dioxide gas, the cutting fluid gradually changes into a lean liquid state without carbon dioxide. The lean cutting fluid from which carbon dioxide has been removed flows smoothly back to the cutting fluid storage unit through the lean liquid outlet 6-6, preparing for the next cycle and ensuring the continuous and stable operation of the entire system.

[0048] like Figure 8 As shown, this embodiment provides a flow chart of a working method of a gas-liquid two-phase cooling and lubrication system based on low-temperature carbon dioxide circulation in the present invention, including the following steps:

[0049] The first step: turning on the cutting fluid delivery pump 1-2, and the cutting fluid cools the cutting unit 4 through the mixing nozzle device 3;

[0050] Step 2: Open the valve of the liquid carbon dioxide bottle 2-4, the pressure of the liquid carbon dioxide drops sharply and it gasifies quickly, and the low-temperature carbon dioxide gas formed enters the mixing nozzle device 3 and mixes with the cutting fluid to form a low-temperature gas-liquid mixture, thereby enhancing the cooling effect on the cutting unit 4;

[0051] Step 3: The low-temperature gas-liquid mixture is subjected to cutting heat from the cutting unit 4. When the temperature of the gas-liquid mixture reaches the reaction temperature of the organic amine capturing the carbon dioxide gas, the organic amine in the liquid begins to capture the carbon dioxide gas and generates carbamate or bicarbonate soluble in water;

[0052] Step 4: The rich cutting fluid after capturing carbon dioxide gas passes through the collection unit 5 and enters the analysis unit 6 for secondary reaction to analyze carbon dioxide gas again;

[0053] Step 5: The lean cutting fluid after analysis flows back into the cutting fluid storage unit 1-1 to realize the recycling of the cutting fluid;

[0054] Step 6: The analyzed carbon dioxide gas returns to the buffer tank 2-1 again, and is re-pressurized into liquid carbon dioxide through the liquefier 2-2, thereby realizing the recycling of carbon dioxide.

Claims

1. A gas-liquid two-phase cooling and lubrication system based on the circulation of low-temperature carbon dioxide, characterized in that: The invention comprises a cutting fluid supply part (1), a carbon dioxide supply part (2), a mixing nozzle device (3), a cutting unit (4), a collecting unit (5) and a analyzing unit (6); the cutting fluid supply part (1) comprises a cutting fluid storage unit (1-1), a delivery pump (1-2) and a first regulating device (1-3); the delivery pump (1-2) delivers the cutting fluid stored in the cutting fluid storage unit (1-1) to the mixing nozzle device (3); the carbon dioxide supply part (2) comprises a buffer tank (2-1), a liquefier (2-2), a booster pump (2-3), a liquid carbon dioxide bottle (2-4), a pressure reducing and stabilizing device (2-5) and a second regulating device (2-6).

2. A gas-liquid two-phase cooling and lubrication system based on low-temperature carbon dioxide circulation according to claim 1, characterized in that: The first regulating device (1-3) regulates the cutting fluid output flow rate range to 5-20 L / min.

3. The gas-liquid two-phase cooling and lubrication system based on the circulation of low-temperature carbon dioxide according to claim 1 is characterized in that: The output pressure range of the outlet of the pressure reducing and stabilizing flow device (2-4) is 0.5-2MPa; the second regulating device (2-5) finely adjusts the mass flow rate of low-temperature carbon dioxide to control the ratio of the output mass flow rate of liquid carbon dioxide to the output mass flow rate of cutting fluid to be 1:

300.

4. The gas-liquid two-phase cooling and lubrication system based on the circulation of low-temperature carbon dioxide according to claim 1 is characterized in that: The mixing nozzle device (3) comprises a first cutting fluid inlet (3-1), a mixing ratio regulating valve body (3-2), a carbon dioxide inlet (3-3), a mixing ratio regulating locking screw (3-4), a first fixing pin (3-5), a second fixing pin (3-6), a mixing chamber sealing ring (3-7), a second cutting fluid inlet (3-8), a mixing chamber (3-9), and a nozzle outlet (3-10); the carbon dioxide inlet (3-3) is disposed on the top of the mixing ratio regulating valve body (3-2) and is used to deliver liquid carbon dioxide in a liquid carbon dioxide bottle (2-3) into the mixing chamber (3-9); the pressure of the liquid carbon dioxide in the mixing chamber (3-9) drops suddenly, and then the liquid carbon dioxide changes into gaseous carbon dioxide, causing the temperature in the mixing chamber (3-9) to drop rapidly; the mixing chamber (3-9) fully mixes low-temperature carbon dioxide gas with the cutting fluid to form a low-temperature gas-liquid mixture, which is ejected in a directional manner through the nozzle outlet (3-10).

5. The gas-liquid two-phase cooling and lubrication system based on the circulation of low-temperature carbon dioxide according to claim 1 is characterized in that: The mixing chamber (3-9) is composed of a first cutting fluid circulation wall (3-2-1) and a second cutting fluid circulation wall (3-9-1); the diameter (3-D) of the cutting fluid annular nozzle is 3-4 mm larger than the diameter (3-C) of the carbon dioxide mixing nozzle; the cross-sectional curve shape of the first cutting fluid circulation wall (3-2-1) is an ellipsoid with a length-to-diameter ratio of 0.7; the cross-sectional curve shape of the second cutting fluid circulation wall (3-9-1) is an ellipsoid with a length-to-diameter ratio of 0.5; a thread is provided on the rotary mixing ratio regulating valve body (3-2); and the mixing ratio regulating distance (3-E) between the first cutting fluid circulation wall (3-2-1) and the second cutting fluid circulation wall (3-9-1) is adjusted by rotating the mixing ratio regulating valve body (3-2).

6. The gas-liquid two-phase cooling and lubrication system based on the circulation of low-temperature carbon dioxide according to claim 1 is characterized in that: The adjustment range of the mixing ratio adjustment distance (3-E) is 0.5-3.5 mm. When the viscosity of the cutting fluid is less than 2 mPa·s, the mixing ratio adjustment distance (3-E) is adjusted between 0.5-2 mm. When the viscosity of the cutting fluid is greater than 2 mPa·s, the mixing ratio adjustment distance (3-E) is adjusted between 2-3.5 mm, thereby controlling the jet diffusion radius of cutting fluids with different viscosities and ensuring the mixing uniformity of cutting fluids with different viscosities and low-temperature carbon dioxide gas.

7. The gas-liquid two-phase cooling and lubrication system based on the circulation of low-temperature carbon dioxide according to claim 1 is characterized in that: The rich-liquid inlet (6-1) of the analyzing unit (6) is connected to the outlet of the collecting unit (5) for flowing the rich-liquid cutting fluid into the reaction device (6-2); the carbon dioxide outlet (6-4) of the analyzing unit (6) is connected to the inlet of the buffer tank (2-1) for collecting the analyzed carbon dioxide gas; and the lean-liquid cutting fluid outlet (6-6) of the analyzing unit (6) is connected to the inlet of the cutting fluid storage unit (1-1) for storing the cutting fluid for easy recycling.

8. The working method of a gas-liquid two-phase cooling lubrication system based on the circulation of low-temperature carbon dioxide according to claim 1, characterized in that: The specific steps are as follows: The first step: turning on the cutting fluid delivery pump (1-2), and the cutting fluid cools the cutting unit (4) through the mixing nozzle device (3); Step 2: Open the valve of the liquid carbon dioxide bottle (2-4), the pressure of the liquid carbon dioxide drops sharply and it gasifies quickly, and the low-temperature carbon dioxide gas formed enters the mixing nozzle device (3) and mixes with the cutting fluid to form a low-temperature gas-liquid mixture, thereby enhancing the cooling effect on the cutting unit (4); Step 3: The low-temperature gas-liquid mixture is subjected to cutting heat from the cutting unit (4). When the temperature of the gas-liquid mixture reaches the reaction temperature of the organic amine capturing the carbon dioxide gas, the organic amine in the liquid begins to capture the carbon dioxide gas and generates carbamate or bicarbonate soluble in water; Step 4: the rich cutting fluid after capturing the carbon dioxide gas passes through the collection unit (5) and enters the analysis unit (6) for secondary reaction to analyze the carbon dioxide gas again; Step 5: the lean cutting fluid after analysis flows back into the cutting fluid storage unit (1-1) to realize the recycling of the cutting fluid; Step 6: The analyzed carbon dioxide gas returns to the buffer tank (2-1) again, and is re-pressurized into liquid carbon dioxide through the liquefier (2-2), thereby realizing the recycling of carbon dioxide.

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