Liquid carbon dioxide cooling waste heat utilization device

Abstract

The utility model relates to the technical field of liquid carbon dioxide production, and discloses a liquid carbon dioxide cooling waste heat utilization device which comprises a liquefaction reaction tank, a carbon dioxide liquefaction mechanism is arranged in the liquefaction reaction tank, and the carbon dioxide liquefaction mechanism comprises a piston plate capable of sliding up and down along the inner wall of the liquefaction reaction tank. The top of the piston plate is connected with a driving air cylinder fixed to the top of the liquefaction reaction tank through a piston rod, a gas inlet, a gas outlet and a liquid outlet are formed in the portion, below the piston plate, of the side wall of the cavity, and a heat circulation mechanism used for utilizing heat generated in the carbon dioxide gas-liquid conversion process is further arranged in the liquefaction reaction tank. The carbon dioxide gas-liquid conversion device is simple in structure, low in manufacturing cost, small in occupied space, small in heat loss and high in waste heat utilization efficiency, the gaseous state and the liquid state of carbon dioxide can be converted only in one liquefaction reaction tank, and heat can be directly utilized in the tank in the carbon dioxide gas-liquid conversion process.

Description

Technical Field

[0001] This utility model relates to the field of liquid carbon dioxide production technology, and in particular to a device for utilizing waste heat from liquid carbon dioxide cooling. Background Technology

[0002] With industrial development and increased energy consumption, carbon dioxide emissions have become an increasingly serious problem. Liquid carbon dioxide is widely used in many industrial processes, but its cooling process generates a large amount of waste heat. Currently, there are many shortcomings in the utilization of waste heat from liquid carbon dioxide cooling; most of the waste heat is not effectively utilized, resulting not only in energy waste but also in environmental impact. To solve these problems, improve energy efficiency, and reduce resource waste and environmental pollution, developing a liquid carbon dioxide cooling waste heat utilization device is of significant practical importance.

[0003] Chinese utility model patent CN218673263U discloses a device for utilizing waste heat from liquid carbon dioxide production. However, this utility model still has the following drawbacks when realizing the production of liquid carbon dioxide and the utilization of waste heat: First, the device has a complex structure and occupies a large space. In order to realize the collection, storage and utilization of waste heat, the device is equipped with multiple tanks, connecting pipes and pumps, which not only increases the manufacturing cost of the equipment, but also increases the difficulty of maintenance and the risk of failure. Second, the device absorbs the heat inside the tank by arranging external water pipes on the outer surface of the liquid processing tank. The contact area between the water pipes and the outer surface of the liquid processing tank is small, the heat transfer efficiency is low, heat is easily lost, and the waste heat collection and utilization rate is low. Utility Model Content

[0004] The purpose of this invention is to provide a liquid carbon dioxide cooling waste heat utilization device with a simple structure and low manufacturing cost. It can realize the conversion of carbon dioxide from gaseous to liquid state in a liquefaction reaction tank, occupying little space. The heat during the carbon dioxide gas-liquid conversion process can be directly utilized in the tank, with little heat loss and high waste heat utilization efficiency.

[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a liquid carbon dioxide cooling waste heat utilization device, including a liquefaction reaction tank, a carbon dioxide liquefaction mechanism is provided inside the liquefaction reaction tank, the carbon dioxide liquefaction mechanism includes a piston plate that can slide up and down along the inner wall of the liquefaction reaction tank, the top of the piston plate is connected to a drive cylinder fixed on the top of the liquefaction reaction tank through a piston rod, and a gas inlet, a gas outlet and a liquid outlet are respectively provided on the side wall of the cavity below the piston plate. The liquefaction reaction tank is also provided with a heat circulation mechanism for utilizing the heat generated during the carbon dioxide gas-liquid conversion process.

[0006] By adopting the above technical solution, the piston rod driven by the driving cylinder moves the piston plate up and down to control the increase or decrease of the cavity below the piston plate. This allows the liquid carbon dioxide in the cavity below the piston plate to be vaporized or the gaseous carbon dioxide to be liquefied. Thus, a single tank can achieve the conversion between the gaseous and liquid states of carbon dioxide. This not only has a simple structure and small footprint, but also low equipment manufacturing and maintenance costs. The heat circulation mechanism is used to collect and utilize the heat generated during the carbon dioxide gas-liquid conversion process. On the one hand, it can assist in the carbon dioxide gas-liquid conversion and improve the conversion efficiency; on the other hand, it can effectively reduce energy waste and improve energy utilization efficiency.

[0007] A further feature of this invention is that the heat circulation mechanism includes multiple sealed heat exchange tubes, with both ends of the sealed heat exchange tubes located in the vacuum cavities on both sides of the piston, and a heat exchange medium is provided inside the liquefied heat exchange tubes.

[0008] By adopting the above technical solution, the heat exchange mechanism uses the heat exchange medium in the heat exchange tube to collect and utilize heat. The heat exchange tube is located inside the liquefaction reaction tank, resulting in high heat exchange efficiency and high heat utilization rate.

[0009] A further feature of this invention is that the heat exchange medium is one of dichlorodifluoromethane, ethanol, or diethyl ether.

[0010] By adopting the above technical solutions, dichlorodifluoromethane, ethanol, or diethyl ether all have advantages such as low boiling point, good chemical stability, and low cost, which can meet the heat exchange requirements.

[0011] A further feature of this invention is that one end of the sealed heat exchange tube located in the cavity above the piston plate is provided with an air bladder that communicates with the interior of the sealed heat exchange tube.

[0012] By adopting the above technical solution, the airbag is used to expand after the heat exchange medium is heated and vaporized. During the expansion process, the airbag continuously occupies the space above the piston plate, which increases the pressure in the cavity above the piston plate. The increased pressure in the cavity above the piston plate will act on the piston plate, adding auxiliary thrust to the piston plate and further improving the liquefaction efficiency of gaseous carbon dioxide in the cavity below the piston plate.

[0013] A further feature of this invention is that the outer wall of one end of the heat exchange tube located in the cavity below the piston is provided with multiple heat-conducting fins.

[0014] By adopting the above technical solution, the heat-conducting fins can further improve the heat transfer efficiency of gaseous or liquid carbon dioxide in the cavity below the heat exchange tube and piston plate, thereby effectively improving the heat collection and utilization efficiency, and thus indirectly improving the gas-liquid conversion efficiency of carbon dioxide.

[0015] The present invention is further configured such that: the gas inlet is connected to the carbon dioxide inlet pipe, the gas outlet is connected to the carbon dioxide outlet pipe, the liquid outlet is connected to the liquid carbon dioxide outlet pipe, and control valves are provided on the carbon dioxide inlet pipe, the carbon dioxide outlet pipe, and the liquid carbon dioxide outlet pipe.

[0016] By adopting the above technical solution, each control valve is used to control the input and output of carbon dioxide gas or liquid into the liquefaction reaction tank through the carbon dioxide inlet pipe, carbon dioxide outlet pipe and liquid carbon dioxide discharge pipe.

[0017] A further feature of this invention is that the cavities on both sides of the piston plate are in a vacuum state.

[0018] By adopting the above technical solution, the cavities on both sides of the piston plate are in a vacuum state, which can ensure that there are no other impurities during the gas-liquid conversion of carbon dioxide in the liquefaction reaction tank. This results in higher purity carbon dioxide in different states, which helps to reduce the interference of impurities on the reaction process, makes the reaction easier to control, and produces high-purity carbon dioxide to meet higher application standards.

[0019] A further feature of this invention is that both the liquefaction reaction vessel and the piston are made of wear-resistant, pressure-resistant, and heat-insulating materials.

[0020] By adopting the above technical solutions, heat loss can be effectively reduced, the internal temperature of the tank can be kept stable, energy utilization efficiency can be improved, and the wear of the piston and the tank itself can be reduced when the piston moves inside the tank, thus extending the service life of the equipment and reducing maintenance costs.

[0021] The beneficial effects of this utility model are:

[0022] 1. By using a drive cylinder to drive the piston rod to move the piston plate up and down, the size of the cavity below the piston plate is controlled to increase or decrease. This allows the liquid carbon dioxide in the cavity below the piston plate to be vaporized or the gaseous carbon dioxide to be liquefied. This achieves the conversion between the gaseous and liquid states of carbon dioxide in a single tank. The equipment has a simple structure, occupies little space, and has low manufacturing and maintenance costs.

[0023] 2. The thermal circulation mechanism of this utility model is used to collect and utilize the heat generated during the carbon dioxide gas-liquid conversion process. On the one hand, it can assist the carbon dioxide gas-liquid conversion and improve the carbon dioxide gas-liquid conversion efficiency; on the other hand, it can effectively reduce energy waste and improve energy utilization efficiency.

[0024] 3. The heat exchange mechanism of this invention utilizes the heat exchange medium in the heat exchange tube for heat collection and utilization. The heat exchange tube is located inside the liquefaction reaction tank, resulting in high heat exchange efficiency and high heat utilization rate. The heat exchange medium is preferably one of dichlorodifluoromethane, ethanol, or diethyl ether. All of these media have advantages such as low boiling point, good chemical stability, and low cost, and can meet the heat exchange requirements.

[0025] 4. The airbag is used to expand after the heat exchange medium is heated and vaporized. During the expansion process, the airbag continuously occupies the space above the piston plate, which increases the pressure in the cavity above the piston plate. The increased pressure in the cavity above the piston plate will act on the piston plate, adding auxiliary thrust to the piston plate, and further improving the liquefaction efficiency of gaseous carbon dioxide in the cavity below the piston plate.

[0026] 5. The heat-conducting fins help the sealed heat exchange tubes to quickly absorb the heat released during the liquefaction of carbon dioxide, further improving the heat transfer efficiency of gaseous or liquid carbon dioxide in the cavity below the piston plate, thereby effectively improving the heat collection and utilization efficiency and indirectly improving the gas-liquid conversion efficiency of carbon dioxide.

[0027] 6. Control valves are installed at the gas inlet, gas outlet, and liquid outlet to control the input and output of carbon dioxide gas or liquid into the liquefaction reactor through the carbon dioxide inlet pipe, carbon dioxide outlet pipe, and liquid carbon dioxide outlet pipe, respectively.

[0028] 7. The cavities on both sides of the piston plate are in a vacuum state, which can ensure that no other impurities are present during the gas-liquid conversion of carbon dioxide in the liquefaction reaction tank. This results in higher purity carbon dioxide in different states, reduces the interference of impurities on the reaction process, makes the reaction easier to control, and produces high-purity carbon dioxide to meet higher application standards.

[0029] 8. Both the liquefaction reaction tank and the piston are made of wear-resistant, pressure-resistant, and heat-insulating materials, which can effectively reduce heat loss, maintain a stable temperature inside the tank, improve energy utilization efficiency, reduce wear on the piston and the tank itself when the piston moves inside the tank, extend the service life of the equipment, and reduce maintenance costs. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the overall structure of a liquid carbon dioxide cooling waste heat utilization device according to the present invention;

[0032] Figure 2 This is a cross-sectional view of a liquid carbon dioxide cooling waste heat utilization device according to the present invention;

[0033] In the diagram, 1. Liquefaction reactor; 2. Carbon dioxide liquefaction mechanism; 21. Piston plate; 22. Piston rod; 23. Drive cylinder; 3. Inlet mechanism; 31. Gas inlet; 32. Carbon dioxide inlet pipe; 33. Control valve one; 4. Discharge mechanism; 41. Gas outlet; 42. Carbon dioxide outlet pipe; 43. Control valve two; 44. Liquid outlet; 45. Liquid carbon dioxide discharge pipe; 46. Control valve three; 5. Thermal circulation mechanism; 51. Sealed heat exchange tube; 52. Heat exchange medium; 53. Gas bag; 54. Heat-conducting fins. Detailed Implementation

[0034] The technical solution of this utility model will now be clearly and completely described with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0035] like Figure 1 As shown, this utility model provides a liquid carbon dioxide cooling waste heat utilization device. A carbon dioxide liquefaction mechanism 2 is provided inside a liquefaction tank 1. The carbon dioxide liquefaction mechanism 2 includes a piston plate 21 that can slide up and down along the inner wall of the liquefaction tank 1. Both the liquefaction tank 1 and the piston are made of wear-resistant, pressure-resistant, and heat-insulating material. The cavities on both sides of the piston plate 21 are in a vacuum state. The top of the piston plate 21 is connected to a drive cylinder 23 fixed to the top of the liquefaction tank 1 via a piston rod 22. A gas inlet 31, a gas outlet 41, and a liquid outlet 44 are respectively provided on the side wall of the cavity below the piston plate 21. The gas inlet 31 is connected to a carbon dioxide inlet pipe 32, the gas outlet 41 is connected to a carbon dioxide outlet pipe 42, and the liquid outlet 44 is connected to the liquid carbon dioxide... The discharge pipe 45 is connected, and control valves are provided on the carbon dioxide inlet pipe 32, the carbon dioxide outlet pipe 42 and the liquid carbon dioxide outlet pipe 45. The liquefaction reaction tank 1 is also equipped with a heat circulation mechanism 5 for utilizing the heat generated during the carbon dioxide gas-liquid conversion process. The heat circulation mechanism 5 includes multiple sealed heat exchange tubes 51. The two ends of the sealed heat exchange tubes 51 are located in the vacuum chambers on both sides of the piston. The sealed heat exchange tubes 51 are equipped with a heat exchange medium 52, which is one of dichlorodifluoromethane, ethanol or diethyl ether. One end of the sealed heat exchange tube 51 located in the cavity above the piston plate 21 is equipped with a gas bladder 53 that communicates with the inside of the sealed heat exchange tube 51. Multiple heat-conducting fins 54 are provided on the outer wall of the end of the heat exchange tube located in the cavity below the piston.

[0036] The working principle of this utility model is as follows: The piston rod 22 is driven by the driving cylinder 23 to move the piston plate 21 up and down, thereby controlling the increase or decrease of the cavity below the piston plate 21. This causes the liquid carbon dioxide in the cavity below the piston plate 21 to be vaporized or the gaseous carbon dioxide to be liquefied, thus achieving the conversion between gaseous and liquid states of carbon dioxide in a single tank. The heat circulation mechanism 5 is used to collect and utilize the heat generated during the carbon dioxide gas-liquid conversion process, assisting in the carbon dioxide gas-liquid conversion. The heat exchange mechanism uses the heat exchange medium 52 in the heat exchange tube to collect and utilize heat. The heat exchange medium 52 has a low boiling point and is easily volatile, meeting the heat exchange requirements. The air bladder 53 is used to expand after the heat exchange medium 52 is heated and vaporized. During the expansion process, the air bladder 53 continuously occupies the space above the piston plate 21, causing the piston... The increased pressure in the cavity above the piston plate 21 acts on the piston plate 21, providing an auxiliary thrust and further improving the liquefaction efficiency of gaseous carbon dioxide in the cavity below the piston plate 21. The heat-conducting fins help the sealed heat exchange tube 51 quickly absorb the heat released during carbon dioxide liquefaction, further improving the heat transfer efficiency between the heat exchange tube and the gaseous or liquid carbon dioxide in the cavity below the piston plate 21. The cavities on both sides of the piston plate 21 are in a vacuum state, ensuring that no impurities are present during the gas-liquid conversion of carbon dioxide in the liquefaction reaction tank 1. This results in higher purity carbon dioxide in different states, reducing interference from impurities in the reaction process, making the reaction easier to control, and producing high-purity carbon dioxide to meet higher application standards.

[0037] The working process of this utility model is as follows:

[0038] 1. The process of preparing liquid carbon dioxide:

[0039] S1: In the initial state, control valve 33 is opened to fill the cavity below piston plate 21 with gaseous carbon dioxide. The pressure in the cavity below piston plate 21 increases. When a certain amount of carbon dioxide is continued to be introduced, the pressure in the cavity below piston plate 21 begins to be greater than the pressure in the cavity above piston plate 21. However, piston plate 21 will not move up and down under the support of piston rod 22.

[0040] S2: Close control valve 33, start drive cylinder 23 to push piston rod 22 to move piston plate 21 downward. The pressure in the cavity below piston plate 21 increases. When a certain pressure is reached, the gaseous carbon dioxide in the cavity below piston plate 21 begins to liquefy and releases heat. The temperature in the cavity below piston plate 21 rises. The heat exchange medium 52 in the sealed heat exchange tube 51 absorbs heat and vaporizes into gas. The gas fills the sealed heat exchange tube 51, causing the gas bag 53 to inflate. During the expansion of the gas bag 53, it continuously occupies the space above piston plate 21, which increases the pressure in the cavity above piston plate 21. The increased pressure in the cavity above piston plate 21 acts on piston plate 21, providing an auxiliary thrust to piston plate 21 and further improving the liquefaction efficiency of gaseous carbon dioxide in the cavity below piston plate 21.

[0041] S3: When the liquefaction process is complete, open control valve 3 46, and liquid carbon dioxide flows out through liquid outlet 44 into liquid carbon dioxide discharge pipe 45.

[0042] 2. The process of preparing gaseous carbon dioxide:

[0043] S1: Control the drive cylinder 23 to pull the piston rod 22 to move in the opposite direction, thereby driving the piston plate 21 to move upward. The volume of the cavity below the piston plate 21 increases and the pressure decreases, while the pressure in the cavity above the piston plate 21 increases. At this time, the air bag 53 is compressed, and the gas in the air bag 53 undergoes a liquefaction reaction and releases heat. The heat is transferred to the cavity below the piston plate 21 through the sealed heat exchange tube 51, and the temperature in the cavity below the piston plate 21 rises. Liquid carbon dioxide absorbs heat and undergoes a vaporization reaction.

[0044] S2: When the vaporization process is complete, open control valve 43, and gaseous carbon dioxide will be discharged through gas outlet 41 into carbon dioxide outlet pipe 42.

Claims

1. A liquid carbon dioxide cooling waste heat utilization device, comprising a liquefaction reaction tank (1), characterized in that: The liquefaction tank (1) is equipped with a carbon dioxide liquefaction mechanism (2). The carbon dioxide liquefaction mechanism (2) includes a piston plate (21) that can slide up and down along the inner wall of the liquefaction tank (1). The top of the piston plate (21) is connected to a drive cylinder (23) fixed on the top of the liquefaction tank (1) through a piston rod (22). The side wall of the cavity below the piston plate (21) is provided with a gas inlet (31), a gas outlet (41), and a liquid outlet (44). The liquefaction tank (1) is also equipped with a heat circulation mechanism (5) for utilizing the heat generated during the carbon dioxide gas-liquid conversion process.

2. The liquid carbon dioxide cooling waste heat utilization device according to claim 1, characterized in that: The heat circulation mechanism (5) includes multiple sealed heat exchange tubes (51), with both ends of the sealed heat exchange tubes (51) located in the vacuum chambers on both sides of the piston, and a heat exchange medium (52) is provided inside the sealed heat exchange tubes (51).

3. The liquid carbon dioxide cooling waste heat utilization device according to claim 2, characterized in that: The heat exchange medium (52) is one of dichlorodifluoromethane, ethanol or diethyl ether.

4. The liquid carbon dioxide cooling waste heat utilization device according to claim 3, characterized in that: The sealed heat exchange tube (51) is provided with an air bladder (53) at one end of the cavity above the piston plate (21) and communicates with the inside of the sealed heat exchange tube (51).

5. The liquid carbon dioxide cooling waste heat utilization device according to claim 3, characterized in that: The heat exchange tube is provided with multiple heat-conducting fins (54) on the outer wall of one end of the cavity below the piston.

6. The liquid carbon dioxide cooling waste heat utilization device according to claim 1, characterized in that: The gas inlet (31) is connected to the carbon dioxide inlet pipe (32), the gas outlet (41) is connected to the carbon dioxide outlet pipe (42), the liquid outlet (44) is connected to the liquid carbon dioxide outlet pipe (45), and control valves are provided on the carbon dioxide inlet pipe (32), the carbon dioxide outlet pipe (42), and the liquid carbon dioxide outlet pipe (45).

7. The liquid carbon dioxide cooling waste heat utilization device according to claim 1, characterized in that: The cavities on both sides of the piston plate (21) are in a vacuum state.

8. The liquid carbon dioxide cooling waste heat utilization device according to claim 1, characterized in that: Both the liquefaction reaction tank (1) and the piston are made of wear-resistant, pressure-resistant, and heat-insulating materials.

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