A temperature control device for liquid carbon dioxide storage

Abstract

The application discloses a temperature control device for liquid carbon dioxide storage, which comprises a temperature sensing device and a heat source control device. The temperature sensing device is internally provided with a conical shell with a narrow upper part and a wide lower part, and stores liquid carbon dioxide with a pressure equal to that of a storage tank. Twenty bulges are designed for heat transfer, so as to ensure that the internal and external temperatures are similar. A good-conducting piston is arranged at the upper part, and the height position of the piston is used to control the connected conductor, so as to control a temperature adjusting device and an alarm device. The application fully meets the temperature control standard of the storage and transportation link, ensures the safety and reliability of the temperature adjustment of the carbon dioxide storage tank, effectively solves the temperature early warning control problem of the liquid carbon dioxide in the storage and transportation process, and has the characteristics of convenient operation, high durability and low cost.

Description

Technical Field

[0001] This invention belongs to the field of instrumentation and control, and relates to a temperature control device based on phase change temperature control technology for use in liquid carbon dioxide storage tanks. Background Technology

[0002] Phase change temperature control technology is a novel thermal control technology developed from phase change energy storage technology. It boasts advantages such as reliable equipment performance, light weight, and no energy consumption, and was initially applied in the aerospace field. With the development of materials science and emerging technologies, it has been gradually applied to various aspects including military and civilian thermal storage, cold chain logistics, and electronic equipment heat dissipation. Current carbon dioxide storage tank technology and carbon dioxide liquefaction storage technology both employ low-temperature, high-pressure liquid storage and transportation methods, placing extremely high demands on temperature. However, traditional temperature control devices mainly rely on sensors such as thermistors and thermocouples to detect and regulate temperature, which are difficult to adapt to the low-temperature, high-pressure carbon dioxide storage environment, exhibiting limitations in sensitivity and durability. Once the temperature inside the tank rises, the liquid carbon dioxide will vaporize and expand, causing a rapid increase in pressure inside the tank, potentially leading to equipment leakage and serious consequences such as environmental pollution and transportation accidents. The phase change temperature control technology employed in this invention monitors temperature through the volume change of the triple point of the substance and uses a spring and a conductor connected to a piston as a trigger for the external heat source control device, thereby achieving sensitive temperature control. This not only effectively avoids the above problems of traditional devices but also reduces operating costs and complexity. Regarding material selection, various low-temperature phase change materials have been discovered that can be used in temperature control. However, these phase change materials all have some drawbacks, making it difficult to achieve ideal results. For example, inorganic materials have advantages such as a wide phase change temperature range, high latent heat per unit mass, and stable chemical properties, but they have low density and poor thermal conductivity. Hydrated salt materials, although having moderate density and high latent heat per unit mass, have poor chemical stability and high supercooling. Summary of the Invention

[0003] This invention addresses the high cost and short lifespan issues of existing liquid carbon dioxide storage tank temperature detection technologies, which rely on fragile electronic components under low-temperature and high-pressure environments. It provides a temperature measurement device primarily implemented using a mechanical structure. This device can rapidly respond to temperature changes in liquid carbon dioxide storage tanks and is also low-cost and highly safe.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a temperature detection device and a temperature control and alarm device that receive temperature detection signals and regulate the temperature inside the liquid carbon dioxide storage tank are connected together; the temperature detection device includes a bottom-sealed piston cylinder (105) and a carbon dioxide storage tank (107), a piston (104) is provided in the piston cylinder, the piston (104) is connected to a spring (101) and moves with the temperature change inside the liquid carbon dioxide storage tank, a conductor hole (103) with an embedded conductor (102) is provided on the surface of the piston cylinder (105), and a bulge (106) is provided on the surface of the carbon dioxide storage tank (107) to enhance heat exchange and buffer the pressure change inside the storage tank, and the inside is filled with liquid carbon dioxide (108).

[0005] The piston (104) cylinder is made of a cylindrical tube, and a conductor hole (103) is opened on the side to communicate with an external temperature control device.

[0006] The conductor hole (103) is embedded with an conductive conductor (102), and the conductor (102) is welded to the external heat source control device (2).

[0007] The piston cylinder (105) is sealed at the upper end and connected to a spring (101) inside. The other end of the spring (101) is connected to a conductive piston (104). The lower end of the piston cylinder (105) is connected to the narrow end of the carbon dioxide storage tank (107).

[0008] The piston (104) moves with the deformation of the spring (101), and when it moves to the conductor hole (103), it connects to the circuit of the external temperature control device.

[0009] The carbon dioxide storage tank (107) is made of a tapered tube, with the wide end sealed and the narrow end connected to the piston cylinder (105).

[0010] The carbon dioxide storage tank (107) is externally provided with a bulge (106) that enhances heat exchange and buffers pressure changes inside the tank.

[0011] The carbon dioxide storage tank (107) is filled with liquid carbon dioxide (108) and nitrogen, and the liquid carbon dioxide (108) and nitrogen are sealed inside the carbon dioxide storage tank (107) by a piston.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] This invention comprises a piston cylinder (105) and a bottom-sealed carbon dioxide storage tank (107). A piston (104) is installed in the piston cylinder (105). The piston (104) is connected to a spring (101) and moves up and down with the temperature change inside the liquid carbon dioxide storage tank. The surface of the piston (104) is provided with a conductor hole (103) for an embedded conductor (102). The conductor (102) is connected to an external heat source control device (2). When the preset temperature inside the liquid carbon dioxide storage tank rises and reaches the phase change point of carbon dioxide, the liquid carbon dioxide in the carbon dioxide storage tank (107)... Carbon dioxide (108) undergoes a phase change to gas, expanding in volume and pushing piston (104) upward. When piston (104) rises to the position where conductors (102) are distributed on piston cylinder (105), conductors (102) at this position will connect to alarm device (202) and temperature regulating device (201), triggering an alarm and cooling the liquid carbon dioxide storage tank. When the temperature of liquid carbon dioxide (108) is lower than the preset temperature, the gas liquefies, shrinks in volume, piston (104) moves downward, circuit is disconnected, and heat source control device (2) stops working. Temperature sensing device (1) consists of interconnected cylindrical and conical tubes, with a compact structure and sensitive volume changes, facilitating installation and maintenance. The design of the bulge (106) on the surface of the carbon dioxide storage tank effectively improves heat exchange and reduces the impact of internal pressure changes on the device. Therefore, this invention can safely and reliably control the temperature in the liquid carbon dioxide storage tank, and has low operating costs and is easy to operate, meeting the requirements for temperature control in the liquid carbon dioxide storage tank under storage and transportation conditions. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the temperature control device of the present invention;

[0015] Among them, 1: temperature sensing device, 101: spring, 102: conductor, 103: conductor hole, 104: piston, 105: piston cylinder, 106: bulge, 107: carbon dioxide storage tank, 108: liquid carbon dioxide, 2: heat source control device, 201: temperature regulation device, 202: alarm device. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings.

[0017] Referring to the accompanying drawings, the present invention comprises two parts: a temperature detection device and a temperature control and execution device. The temperature sensing device (1) is composed of a spring (101), a conductor (102), a conductor hole (103), a piston (104), a piston cylinder (105), a bulge (106), a carbon dioxide storage tank (107), and liquid carbon dioxide (108). The heat source control device (2) includes a temperature adjustment device (201) and an alarm device (202).

[0018] The temperature sensing device (1) includes a hollow, insulated cylindrical piston cylinder (105) with three circular conductor holes (103) on each of its symmetrical sides. The conductor holes (103) are filled with a highly conductive conductor (102) to ensure the piston (104) can move. The bottom of the insulated cylindrical piston cylinder (105) is connected to a conical, insulated, and thermally conductive carbon dioxide storage tank (107). The top of the insulated cylindrical piston cylinder (105) is closed, with a spring (101) fixed to it. A piston (104) is connected to the lower part of the spring (101). The piston (104) is a highly conductive conductor and is tightly connected to the inner wall of the insulated cylindrical piston cylinder (105). When the highly conductive conductor (102) embedded in the insulated cylindrical piston cylinder (105) comes into contact with the piston (104), the piston (104) can conduct current between the two conductors (102) at the same height. Meanwhile, the piston (104) has good airtightness, which can prevent gas exchange between the upper and lower sides. The three pairs of conductors (102) are distributed at a certain designed spacing. The spacing between the conductors (102) will be designed according to the specific use environment, and they are not connected to each other when there is no piston (104) in the middle. Each conductor (102) is connected to an external actuator. The lower carbon dioxide storage tank (107) is filled with a certain mass of liquid carbon dioxide (108). The edge of the carbon dioxide storage tank (107) is provided with multiple bulges (106) to increase the heat exchange area, improve the heat exchange efficiency, and help the carbon dioxide (108) inside the carbon dioxide storage tank (107) exchange heat with the outside.

[0019] The specific positions of the three pairs of conductors (102) in the piston cylinder (105) are as follows: the bottom conductor (102) requires that when the device temperature reaches the warning temperature (a preset temperature value that is lower than a certain value of the critical temperature of carbon dioxide in the external environment), the piston just contacts this pair of conductors and conducts the circuit; the middle conductor (102) requires that when the carbon dioxide reaches the danger temperature (a preset temperature value between the warning temperature and the critical temperature), the piston just contacts this pair of conductors and conducts the circuit; the top conductor (102) requires that when the device temperature reaches or is slightly higher than the critical temperature, the piston just contacts this pair of conductors and conducts the circuit.

[0020] Three pairs of conductors (102) extend outwards from bottom to top, each with a wire connecting to a different actuator. The bottom conductor (102) is only connected to the alarm device (202) to inform the device that the temperature is approaching the set danger value. In addition to the alarm device (202), the middle conductor (102) is also connected to the temperature regulating device (201). When it is connected, it can control the temperature regulating device (201) to regulate the temperature of the heat source. After the top conductor (102) is connected, it can improve the efficiency of the temperature regulating device (201) and can also be used to add equipment according to the usage environment.

[0021] The piston (104) is relatively long, which ensures that the lower part of the piston (104) will not detach from the lowest conductor (102) during the upward movement.

[0022] The space above the piston (104) is close to a vacuum, and a seal is used to maintain its vacuum level.

[0023] The method of using this invention is as follows:

[0024] Taking the internal temperature detection and control of a large carbon dioxide storage tank as an example, when the external carbon dioxide temperature is lower than the warning temperature, the piston (104) is not connected to any set of conductors, and the device has no feedback.

[0025] When the external carbon dioxide temperature is higher than the warning temperature but lower than the danger temperature, the piston (104) is in equilibrium between the lower conductor (102) and the middle conductor (102). At this time, the lowermost first set of conductors (102) is connected by the piston (104), while the middle and upper sets of conductors (102) are not connected. The actuator connected to the lowermost conductor (102), such as the heat source control device (2), is energized and starts operating to control the temperature of the external carbon dioxide storage tank to remain below the warning temperature.

[0026] When the ambient carbon dioxide temperature is higher than the danger temperature but lower than the critical temperature, the piston (104) is positioned between the middle and upper conductors (102), the middle conductor (102) is conducting, the alarm device (202) connected to the lower conductor is still running, and the temperature regulating device (201) connected to the middle conductor starts to run.

[0027] When the external carbon dioxide temperature reaches the critical temperature or above, the piston (104) reaches the equilibrium position above the uppermost conductor (102), all conductors (102) are turned on, and all actuators, including the actuators connected to the uppermost conductor (102), are turned on. Safety measures with significant economic losses and irreversible effects, such as pressure relief valves, and personnel safety alarms, begin to operate.

Claims

1. A temperature control device for use in a liquid carbon dioxide storage tank, characterized in that: The device includes a temperature sensing device (1) and a heat source control device (2); the temperature sensing device (1) includes a spring (101), a conductor (102), a conductor hole (103), a piston (104), a piston cylinder (105), a bulge (106), a carbon dioxide storage tank (107), and liquid carbon dioxide (108); the carbon dioxide storage tank (107) contains liquid carbon dioxide (108), the outer surface of the carbon dioxide storage tank (107) is provided with a bulge (106), the carbon dioxide storage tank (107) is connected to the piston cylinder (105), and the top of the piston cylinder (105) is... The upper end of the spring (101) is connected to the lower end of the piston (104), the piston (104) is placed in the piston cylinder (105), the piston cylinder (105) has a conductor hole (103) on the side, a conductor (102) is fixed in the conductor hole (103), and the piston (104) is in contact with the conductor (102) on the side wall; the heat source control device (2) includes a temperature regulating device (201) and an alarm device (202), the heat source control device (2) is externally connected to the conductor hole (103), and the temperature sensing device (1) is connected to the heat source control device (2).

2. The temperature control device according to claim 1, characterized in that: The piston cylinder (105) is cylindrical, and the carbon dioxide storage tank (107) is conical. The carbon dioxide storage tank (107) is sealed to the cylindrical piston cylinder (105). The interior of the carbon dioxide storage tank (107) is in communication with the piston cylinder (105). The wide end of the carbon dioxide storage tank (107) is sealed, and the narrow end of the carbon dioxide storage tank (107) is connected to the piston cylinder (105). A conductor hole (103) communicating with an external heat source control device (2) is opened on the side of the piston cylinder (105).

3. The temperature control device according to claim 1, characterized in that: The upper part of the spring (101) is fixed to the upper end of the piston cylinder (105), and the lower part of the spring (101) is connected to the piston (104). The piston (104) is placed in the piston cylinder (105) and the piston (104) is in contact with the conductor (102).

4. The temperature control device according to claim 1, characterized in that: The piston (104) moves along the axial direction of the piston cylinder (105) under the combined action of liquid carbon dioxide (108) and spring (101). When the piston (104) moves to the conductor hole (103), the piston (104) contacts the conductor (102), and the conductor (102) is connected to the circuit of the external heat source control device (2).

5. The temperature control device according to claim 1, characterized in that: The carbon dioxide storage tank (107) is filled with liquid carbon dioxide (108), and the liquid carbon dioxide (108) is sealed in the carbon dioxide container (107) by a piston (104).

6. The temperature control device for a liquid carbon dioxide storage tank according to claim 1, characterized in that: A conductor (102) is welded inside the conductor hole (103), and the conductor (102) is connected to the temperature regulation device (201) and the alarm device (202) through a circuit.

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