A skid-mounted device for dry ice tail gas recovery

Abstract

The present invention relates to the technical field of dry ice processing, and particularly relates to a skid-mounted device for dry ice tail gas recovery, including: a heat exchange and compression assembly for heat exchange and compression of the tail gas; a liquefaction and purification assembly for dehydration, drying, cryogenic liquefaction and gas-liquid separation of the heat-exchanged and compressed tail gas; a data acquisition module including a temperature acquisition unit for acquiring the temperature of the heat exchanger, a flow rate acquisition unit for acquiring the tail gas emission flow rate of the dry ice machine, and a dielectric constant acquisition unit for acquiring the dielectric constant of the liquefied carbon dioxide; a control module for secondarily determining whether the heat exchange and compression of the tail gas is qualified according to the heat response index of the heat exchanger when it is determined that the heat exchange and compression of the tail gas is unqualified according to the temperature variance, or for determining the reason for the unqualified heat exchange and compression of the tail gas according to the pressure difference, and for determining whether the liquefaction and purification of the tail gas is qualified according to the dielectric matching degree, thereby improving the dry ice tail gas recovery efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of dry ice processing, and particularly to a skid-mounted device for dry ice tail gas recovery. Background Art

[0002] Dry ice tail ice recovery refers to a technical system for collecting, purifying, and recycling carbon dioxide tail gas generated during the manufacturing or use of dry ice, aiming to reduce greenhouse gas emissions and achieve resource recycling.

[0003] A skid-mounted device is a highly integrated form of equipment combination. Usually, multiple related devices are integrated within a single overall framework to form a complete functional equipment unit. The characteristics of this device include a compact structure, easy migration and installation, and full consideration of safety and stability during the design and manufacturing processes.

[0004] Chinese Patent Application Publication No.: CN119588109A, discloses a tail gas recovery device for preparing dry ice, including a tail gas pipe. The left end of the tail gas pipe is connected to the tail gas outlet of the dry ice production equipment, and the right end of the tail gas pipe is connected to an adsorption tower. A carbon dioxide adsorption component is fixedly installed inside the adsorption tower. The carbon dioxide in the tail gas is adsorbed by the carbon dioxide adsorption component in the adsorption tower, and then the carbon dioxide is collected by a collection hood. The collected carbon dioxide gas flow enters the connecting pipe along the output pipe, and then is pressurized by a booster pump and introduced into a compressor. The compressor compresses the carbon dioxide gas, which is then used as a raw material for preparing dry ice. Compared with the previous method of directly introducing the tail gas into the compressor, this method can purify the tail gas, increase the content of carbon dioxide, and thus enable the high-temperature liquid state after compression by the compressor to meet the requirements for manufacturing dry ice.

[0005] It can be seen that although the above technical solution realizes the purification and compression of carbon dioxide through the adsorption tower and the booster pump, it does not consider the temperature variance of the heat exchanger, the heat response index, and the pressure difference of the compressed tail gas during the heat exchange compression process, and cannot evaluate the compression efficiency in real time, resulting in the problem of low dry ice tail gas recovery efficiency. Summary of the Invention

[0006] Therefore, the present invention provides a skid-mounted device for dry ice tail gas recovery to overcome the problem in the prior art that the temperature variance of the heat exchanger, the heat response index, and the pressure difference of the compressed tail gas are not considered during the heat exchange compression process, and the compression efficiency cannot be evaluated in real time, resulting in low dry ice tail gas recovery efficiency.

[0007] To achieve the above object, the present invention provides a skid-mounted device for dry ice tail gas recovery, including:

[0008] A heat exchange and compression assembly for heat exchanging and compressing tail gas, comprising a heat exchanger, an airbag for buffering the tail gas communicated with the tail gas outlet of the heat exchanger, and a compressor with one end connected to the output end of the airbag and the other end communicated with the compressed tail gas inlet of the heat exchanger. Wherein, tail gas inlets and tail gas outlets are respectively formed on the two side walls at the two ends of the heat exchanger, a compressed tail gas inlet is formed at the top of the heat exchanger, and a compressed tail gas outlet is formed at the bottom of the heat exchanger;

[0009] A liquefaction and purification assembly connected to the output end of the heat exchange and compression assembly, comprising a dryer for dehydrating and drying the heat-exchanged and compressed tail gas communicated with the compressed tail gas outlet of the heat exchanger, a cooler for cryogenic liquefaction connected to the output end of the dryer, and a gas-liquid separator for gas-liquid separation connected to the output end of the cooler;

[0010] A data acquisition module, comprising a temperature acquisition unit for acquiring the temperature of the heat exchanger, a flow rate acquisition unit for acquiring the tail gas emission flow rate of the dry ice machine, and a dielectric constant acquisition unit for acquiring the dielectric constant of the liquefied carbon dioxide;

[0011] A control module, which is respectively connected to the heat exchange and compression assembly, the liquefaction and purification assembly, and the data acquisition module, and is used for determining that the heat exchange and compression of the tail gas does not meet the preset standard according to the temperature variance of the heat exchanger, and then determining whether the heat exchange and compression of the tail gas meets the preset standard again according to the heat response index of the heat exchanger, or, determining the reason why the heat exchange and compression of the tail gas does not meet the preset standard according to the pressure difference of the compressed tail gas, and determining whether the liquefaction and purification of the tail gas meets the preset standard according to the dielectric matching degree of the liquefied carbon dioxide. Wherein, the reasons include that the transportation of the compressed tail gas leaks or the compressor fails, resulting in the blockage of the second flow channel.

[0012] Further, a first flow channel and a second flow channel are arranged inside the heat exchanger. The first flow channel is respectively communicated with the tail gas inlet and the tail gas outlet, and the second flow channel is respectively communicated with the compressed tail gas inlet and the compressed tail gas outlet.

[0013] Further, the control module determines whether the heat exchange and compression of the tail gas meets the preset standard according to the temperature variance of the heat exchanger, wherein,

[0014] If the temperature variance is less than the first preset temperature variance, it is determined that the heat exchange and compression of the tail gas meets the preset standard, and the tail gas meeting the preset standard is transported to the liquefaction and purification assembly;

[0015] If the temperature variance is greater than or equal to the first preset temperature variance and less than the second preset temperature variance, it is determined that the heat exchange and compression of the tail gas does not meet the preset standard, and it is determined again whether the heat exchange and compression of the tail gas meets the preset standard according to the heat response index of the heat exchanger;

[0016] If the temperature variance is greater than or equal to the second preset temperature variance, it is determined that the heat exchange compression of the tail gas does not meet the preset standard, and the reason why the heat exchange compression of the tail gas does not meet the preset standard is determined according to the pressure difference of the compressed tail gas;

[0017] The temperature variance is determined by the temperature collected by the temperature acquisition unit.

[0018] Further, the control module secondarily determines whether the heat exchange compression of the tail gas meets the preset standard according to the heat response index of the heat exchanger, where

[0019] If the heat response index is less than the preset heat response index, it is determined that the heat exchange compression of the tail gas meets the preset standard, and the tail gas that meets the preset standard is transported to the liquefaction and purification component;

[0020] If the heat response index is greater than or equal to the preset heat response index, it is determined that the heat exchange compression of the tail gas does not meet the preset standard, and the rotation speed of the compressor is increased according to the difference between the preset heat response index and the heat response index.

[0021] Further, the heat response index is the ratio of the response duration required for the central temperature of the heat exchanger to reach a steady state to the preset response duration when the flow rate of the dry ice tail gas entering the first flow channel exceeds the preset discharge flow rate.

[0022] Further, the control module is provided with several speed adjustment methods for increasing the rotation speed of the compressor, and each speed adjustment method has a different increase amplitude for the rotation speed of the compressor.

[0023] Further, the control module determines the reason why the heat exchange compression of the tail gas does not meet the preset standard according to the pressure difference of the compressed tail gas, where

[0024] If the pressure difference is less than the preset pressure difference, it is determined that the reason why the heat exchange compression of the tail gas does not meet the preset standard is that there is a leakage in the transportation of the compressed tail gas;

[0025] If the pressure difference is greater than or equal to the preset pressure difference, it is determined that the reason why the heat exchange compression of the tail gas does not meet the preset standard is that the second flow channel is blocked due to the failure of the compressor.

[0026] Further, the control module determines whether the liquefaction and purification of the tail gas meet the preset standard according to the dielectric matching degree of the liquefied carbon dioxide, where

[0027] If the dielectric matching degree is less than the preset matching degree, it is determined that the liquefaction and purification of the tail gas do not meet the preset standard, and the gas-liquid separation duration of the gas-liquid separator is increased according to the difference between the preset matching degree and the dielectric matching degree;

[0028] If the dielectric matching degree is greater than or equal to the preset matching degree, it is determined that the liquefaction and purification of the tail gas meet the preset standard.

[0029] Further, the dielectric matching degree is the ratio between the dielectric constant of liquid carbon dioxide and a preset dielectric constant.

[0030] Further, the increase amplitude of the gas-liquid separation time of the gas-liquid separator is positively correlated with the matching difference, where the matching difference is the difference between the preset matching degree and the dielectric matching degree.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention pre-cools the tail gas through the first flow channel of the heat exchanger and recovers the compression heat through the second flow channel to form a closed thermodynamic cycle, reducing the system energy consumption; an airbag is arranged at the front end of the compressor to effectively reduce the pulse pressure of the tail gas emission, improve the stability of the compression process, and extend the equipment life; a dual standard of temperature variance and heat response index is adopted to evaluate whether the heat exchange and compression of the tail gas meet the preset standard, avoiding misjudgment by a single parameter and ensuring the stability of the compressed tail gas; according to the dielectric matching degree, which is the ratio of the dielectric constant of liquid carbon dioxide to the preset value, it directly reflects the impurity residue amount, avoiding the misjudgment risk of traditional conductivity detection.

[0032] Further, the present invention is provided with a temperature variance. According to the different influences of the first flow rate stage, the second flow rate stage, and the third flow rate stage on the stability of the tail gas heat exchange and compression, different weights are assigned to the temperature variances of each flow rate stage, so that the second flow rate stage, that is, the normal working condition, dominates the determination, while taking into account the sudden fluctuations of high and low loads. Through the weighted average variance, the interference of a single flow rate stage on the overall determination is avoided, and the temperature fluctuation characteristics of the entire process of the heat exchanger are more truly reflected, thereby improving the reliability of the evaluation index.

[0033] Further, the present invention sets a heat response index to perform a secondary determination on whether the heat exchange and compression of the tail gas meet the preset standard when the temperature variance is greater than or equal to a first preset temperature variance and less than a second preset temperature variance. By detecting the temperature response duration under the condition of sudden flow rate change, the flow rate fluctuation is directly associated with the temperature dynamic response, thereby improving the accuracy of the evaluation.

[0034] Further, the present invention realizes the intelligent distinction between leakage and blockage through the determination of the pressure difference threshold, avoiding the blindness of traditional manual inspection; when the pressure difference is lower than the preset value, the leakage of the conveying system is accurately locked, and when it is higher than the preset value, the compressor failure is determined, thereby improving the accuracy of fault identification.

[0035] Further, the present invention sets that the increase amplitude of the gas-liquid separation time of the residual gas-liquid separator is positively correlated with the matching difference, where the matching difference is the difference between the preset matching degree and the dielectric matching degree, thereby realizing the precise control of the increase amplitude of the gas-liquid separation time of the gas-liquid separator.

[0036] Furthermore, the present invention quantifies the liquefaction purification effect through the dielectric matching degree, and improves the purification effect through the threshold determination and difference ratio adjustment mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 FIG. 1 is a schematic structural diagram of a skid-mounted device for dry ice tail gas recovery according to an embodiment of the present invention;

[0038] Figure 2 FIG. 2 is a flowchart for determining whether the heat exchange compression of the tail gas meets a preset standard according to the temperature variance in an embodiment of the present invention;

[0039] Figure 3 FIG. 3 is a flowchart for determining the reason why the heat exchange compression of the tail gas does not meet the preset standard in an embodiment of the present invention;

[0040] Figure 4 FIG. 4 is a flowchart for determining whether the liquefaction purification of the tail gas meets a preset standard in an embodiment of the present invention;

[0041] In the figures, 1, heat exchanger; 2, airbag; 3, compressor; 4, dryer; 5, cooler; 6, gas-liquid separator. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] In order to make the objectives and advantages of the present invention more clear, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0043] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present invention and do not limit the protection scope of the present invention.

[0044] It should be noted that the data in this embodiment are obtained through comprehensive analysis and evaluation of the historical test data and corresponding historical test results of the present invention in the three months before this test. Those skilled in the art can understand that the determination method of the present invention for a single above-mentioned parameter can be to select the value with the highest proportion according to the data distribution as the preset standard parameter, use weighted summation to obtain the value as the preset standard parameter, substitute each historical data into a specific formula and use the value obtained by using this formula as the preset standard parameter or other selection methods, as long as it satisfies that the method of the present invention can clearly define different specific situations in the single determination process through the obtained values.

[0045] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4As shown, they are respectively the structural schematic diagram of the skid-mounted device for dry ice tail gas recovery according to the embodiment of the present invention; the flowchart of the embodiment of the present invention for determining whether the heat exchange and compression of the tail gas meet the preset standard according to the temperature variance; the flowchart of the embodiment of the present invention for determining the reason why the heat exchange and compression of the tail gas do not meet the preset standard; the flowchart of the embodiment of the present invention for determining whether the liquefaction and purification of the tail gas meet the preset standard.

[0046] Please refer to Figure 1 As shown, the embodiment of the present invention provides a skid-mounted device for dry ice tail gas recovery, including:

[0047] A heat exchange and compression assembly, which is used for heat exchange and compression of the tail gas, including a heat exchanger 1, an airbag 2 for buffering the tail gas communicated with the tail gas output port of the heat exchanger 1, and a compressor 3 with one end connected to the output end of the airbag 2 and the other end communicated with the compressed tail gas input port of the heat exchanger 1. Among them, the two side walls at both ends of the heat exchanger 1 are respectively provided with a tail gas input port and a tail gas output port, the top of the heat exchanger 1 is provided with a compressed tail gas input port, and the bottom of the heat exchanger 1 is provided with a compressed tail gas output port;

[0048] A liquefaction and purification assembly, which is connected to the output end of the heat exchange and compression assembly, including a dryer 4 communicated with the compressed tail gas output port of the heat exchanger 1 for dehydrating and drying the heat-exchanged and compressed tail gas, a cooler 5 connected to the output end of the dryer 4 for low-temperature liquefaction, and a gas-liquid separator 6 connected to the output end of the cooler 5 for gas-liquid separation;

[0049] A data acquisition module, which includes a temperature acquisition unit for acquiring the temperature of the heat exchanger 1, a flow rate acquisition unit for acquiring the tail gas emission flow rate of the dry ice machine, and a dielectric constant acquisition unit for acquiring the dielectric constant of the liquefied carbon dioxide;

[0050] A control module, which is respectively connected to the heat exchange and compression assembly, the liquefaction and purification assembly, and the data acquisition module, and is used for determining whether the heat exchange and compression of the tail gas do not meet the preset standard according to the temperature variance of the heat exchanger 1, and then secondarily determining whether the heat exchange and compression of the tail gas meet the preset standard according to the heat response index of the heat exchanger 1, or, determining the reason why the heat exchange and compression of the tail gas do not meet the preset standard according to the pressure difference of the compressed tail gas and determining whether the liquefaction and purification of the tail gas meet the preset standard according to the dielectric matching degree of the liquefied carbon dioxide. Among them, the reasons include leakage in the transportation of the compressed tail gas or blockage of the second flow channel caused by compressor failure.

[0051] Specifically, the heat exchanger internally has a first flow channel and a second flow channel. The first flow channel is respectively communicated with the tail gas input port and the tail gas output port, and the second flow channel is respectively communicated with the compressed tail gas input port and the compressed tail gas output port. Among them, heat exchange is realized between the dry ice tail gas in the first flow channel and the compressed tail gas in the second flow channel.

[0052] In this embodiment, the heat exchanger 1 is a shell-and-tube heat exchanger, the first flow channel is the tube side, and the second flow channel is the shell side; the compressed tail gas exchanges heat with the dry ice tail gas in the tube side; the temperature of the dry ice tail gas is lower than that of the compressed tail gas.

[0053] In this embodiment, the temperature acquisition unit is arranged at the center of the inner wall of the shell of the heat exchanger 1, and the temperature acquisition unit is a temperature sensor; the flow rate acquisition unit is arranged at the exhaust port of the dry ice machine tail gas, and it is a turbine flowmeter; the dielectric constant acquisition unit is installed at the outlet of the gas-liquid separator 6, and it is a microwave resonance sensor.

[0054] In this embodiment, the specific structure of the control module is not limited. It itself and each unit therein can be composed of logic components, and the logic components include field programmable components, computers or microprocessors in the computer.

[0055] Please refer to Figure 2 As shown, specifically, the control module determines whether the heat exchange compression of the tail gas meets the preset standard according to the temperature variance of the heat exchanger 1, where

[0056] If the temperature variance is less than the first preset temperature variance of 0.45 °C 2 , it is determined that the heat exchange compression of the tail gas meets the preset standard, and the tail gas that meets the preset standard is transported to the liquefaction and purification component;

[0057] If the temperature variance is greater than or equal to the first preset temperature variance and less than the second preset temperature variance, it is determined that the heat exchange compression of the tail gas does not meet the preset standard, and it is further determined whether the heat exchange compression of the tail gas meets the preset standard according to the heat response index of the heat exchanger 1;

[0058] If the temperature variance is greater than or equal to the second preset temperature variance of 0.68 °C 2 , it is determined that the heat exchange compression of the tail gas does not meet the preset standard, and the reason why the heat exchange compression of the tail gas does not meet the preset standard is determined according to the pressure difference of the compressed tail gas.

[0059] Specifically, a temperature variance less than the first preset temperature variance indicates that the tail gas and the compressed tail gas are fully heat exchanged in the heat exchanger and the temperature distribution is uniform; a temperature variance greater than or equal to the first preset temperature variance and less than the second preset temperature variance indicates that there is local thermal imbalance, which may be caused by flow rate fluctuations or a decrease in the efficiency of the heat exchanger and requires further analysis;

[0060] A temperature variance greater than or equal to the second preset temperature variance indicates significant thermal imbalance in the heat exchanger.

[0061] Through the three-level progressive determination of temperature variance, heat response index and pressure difference, a closed-loop control from performance monitoring to fault location is achieved, meeting the requirements of industrial systems for real-time performance and reliability.

[0062] In this embodiment, the value range of the first preset temperature variance is (0.35 °C 2 , 0.50 °C 2 ), and the value range of the second preset temperature variance is (0.60 °C 2 , 0.75 °C 2 ). Preferably, the first preset temperature variance is selected as 0.45 °C 2 , and the second preset temperature variance is selected as 0.68 °C 2 .

[0063] The process of obtaining the temperature variance includes:

[0064] Dividing the heat exchange process into a first flow stage, a second flow stage, and a third flow stage according to the flow rate of the tail gas discharge port of the dry ice machine collected by the flow rate collection unit;

[0065] The temperature collection unit collects the temperature at the center of the inner wall of the shell of the heat exchanger 1 every 5 s in each flow stage, and obtains the variances of the center of the inner wall of the shell in each flow stage, denoted as the first variance, the second variance, and the third variance;

[0066] The temperature variance is the weighted average variance of the first variance, the second variance, and the third variance. Among them, the weight of the first variance is 0.2, the weight of the second variance is 0.5, and the weight of the third variance is 0.3; the tail gas flow rate of the dry ice machine in the first flow stage is 40% - 50% of the design value; the tail gas flow rate of the dry ice machine in the second flow stage is 80% - 100% of the design value; the tail gas flow rate of the dry ice machine in the third flow stage is 110% - 130% of the design value; the design value of the tail gas flow rate of the dry ice machine in this embodiment is set to 4 cubic meters per minute, and the average value of several experimental data is taken as the design value by testing the tail gas emission of the dry ice machine at the rated power.

[0067] Specifically, the control module secondarily determines whether the heat exchange compression of the tail gas meets the preset standard according to the heat response index of the heat exchanger 1, where

[0068] If the heat response index is less than the preset heat response index 1.2, it is determined that the heat exchange compression of the tail gas meets the preset standard, and the tail gas that meets the preset standard is transported to the liquefaction and purification component;

[0069] If the heat response index is greater than or equal to the preset heat response index, it is determined that the heat exchange compression of the tail gas does not meet the preset standard, and the rotation speed of the compressor 3 is increased according to the difference between the preset heat response index and the heat response index.

[0070] Specifically, the thermal response index is the ratio of the response duration required for the central temperature of the housing of the heat exchanger 1 to reach a steady state to the preset response duration of 10 min when the flow rate of the dry ice tail gas entering the first flow channel exceeds the preset discharge flow rate of 3.6 m³ / min.

[0071] In this embodiment, the value range of the preset response duration is (8 min, 12 min). Preferably, the preset response duration is selected as 10 min; the value range of the preset thermal response index is (1.08, 1.25). Preferably, the preset thermal response index is selected as 1.2; an infrared thermometer needs to be used to continuously monitor the temperature in the central area of the housing. When the temperature fluctuation amplitude within 5 consecutive minutes is less than ±0.5 °C, it means that the central temperature of the housing of the heat exchanger 1 reaches a steady state.

[0072] Specifically, the control module is provided with several speed adjustment methods for increasing the speed of the compressor 3, where

[0073] If the difference in the thermal response index is less than the first preset difference in the thermal response index of 0.22, the speed of the compressor 3 is increased to the corresponding value using the first adjustment coefficient of 1.02;

[0074] If the difference in the thermal response index is greater than or equal to the first preset difference in the thermal response index and less than the second preset difference in the thermal response index of 0.45, the speed of the compressor 3 is increased to the corresponding value using the second adjustment coefficient of 1.04;

[0075] If the difference in the thermal response index is greater than or equal to the second preset difference in the thermal response index, the speed of the compressor 3 is increased to the corresponding value using the third adjustment coefficient of 1.06; the difference in the thermal response index is the difference between the preset thermal response index and the thermal response index.

[0076] Please refer to Figure 3 As shown, specifically, the control module determines the reason why the heat exchange compression of the tail gas does not meet the preset standard based on the pressure difference of the compressed tail gas, where

[0077] If the pressure difference is less than the preset pressure difference of 20 kPa, it is determined that the reason for the heat exchange compression of the tail gas not meeting the preset standard is a leakage in the transportation of the compressed tail gas;

[0078] If the pressure difference is greater than or equal to the preset pressure difference, it is determined that the reason for the heat exchange compression of the tail gas not meeting the preset standard is that the compressor 3 fails, resulting in a blockage in the second flow channel.

[0079] Specifically, when the pressure difference of the compressed tail gas is lower than the preset value, it indicates that there is a pressure loss during the transportation of the tail gas. At this time, the module preferentially determines that the tail gas is leaking, such as the seal failure at the pipeline connection, the valve not being closed, or the container being damaged, etc. The leakage will cause the tail gas to escape from the high-pressure area to the low-pressure area, and the device cannot maintain a stable compression pressure, resulting in a significant decrease in the pressure difference.

[0080] A pressure difference higher than the preset value indicates an increase in flow resistance. At this time, it is determined that the compressor 3 fails, resulting in the blockage of the second flow path and the accumulation of particulate matter. The blockage of the compressor 3 will hinder the flow of the tail gas, causing the upstream pressure to increase and the downstream pressure to decrease, and the pressure difference will increase accordingly.

[0081] Please refer to Figure 4 As shown, specifically, the control module determines whether the liquefaction and purification of the tail gas meet the preset standards according to the dielectric matching degree of the liquefied carbon dioxide, where

[0082] If the dielectric matching degree is less than the preset matching degree of 0.94, it is determined that the liquefaction and purification of the tail gas do not meet the preset standards, and the gas-liquid separation time of the gas-liquid separator 6 is increased according to the difference between the preset matching degree and the dielectric matching degree;

[0083] If the dielectric matching degree is greater than or equal to the preset matching degree, it is determined that the liquefaction and purification of the tail gas meet the preset standards.

[0084] Specifically, the mixing of non-condensable gas impurities in the liquid carbon dioxide will cause the dielectric constant of the liquid carbon dioxide to decrease.

[0085] Specifically, the dielectric matching degree is the ratio of the dielectric constant of the liquid carbon dioxide to the preset dielectric constant of 1.59.

[0086] In this embodiment, the preset dielectric constant is selected according to the dielectric constant of high-purity liquid carbon dioxide marked in the NIST database as 1.59.

[0087] Specifically, the increase amplitude of the gas-liquid separation time of the gas-liquid separator 6 is positively correlated with the matching difference. Among them, the positive correlation is, for example, a linear positive correlation or a non-linear positive correlation. The linear slope of the linear positive correlation is not specifically limited. It can be understood that the larger the matching difference, the greater the increase amplitude of the gas-liquid separation time of the gas-liquid separator 6; the matching difference is the difference between the preset matching degree and the dielectric matching degree.

[0088] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0089] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A skid-mounted device for recovering dry ice tail gas, characterized in that: include: A heat exchange compression assembly, which is used to perform heat exchange and compression on exhaust gas, comprises a heat exchanger, an air bag connected to the exhaust gas output port of the heat exchanger and used to buffer the exhaust gas, and a compressor connected to the output end of the air bag at one end and connected to the compressed exhaust gas input port of the heat exchanger at the other end, wherein the exhaust gas input port and the exhaust gas output port are respectively provided on the side walls at both ends of the heat exchanger, the compressed exhaust gas input port is provided at the top of the heat exchanger, and the compressed exhaust gas output port is provided at the bottom of the heat exchanger; A liquefaction and purification component connected to the output end of the heat exchange and compression component, comprising an adsorption dryer connected to the compressed tail gas output port of the heat exchanger for dehydrating and drying the tail gas compressed by heat exchange, a cooling machine connected to the output end of the adsorption dryer for low-temperature liquefaction, and a gas-liquid separator connected to the output end of the cooling machine for gas-liquid separation; A data acquisition module, comprising a temperature acquisition unit for acquiring the temperature of the heat exchanger, a flow acquisition unit for acquiring the exhaust flow of the dry ice machine, and a dielectric constant acquisition unit for acquiring the dielectric constant of the liquefied carbon dioxide of the liquefaction and purification component; A control module, which is respectively connected to the heat exchange compression component, the liquefaction and purification component and the data acquisition module, and is used to determine whether the heat exchange compression of the exhaust gas meets the preset standard based on the thermal response index of the heat exchanger when the heat exchange compression of the exhaust gas does not meet the preset standard based on the temperature variance of the heat exchanger, or to determine the reason why the heat exchange compression of the exhaust gas does not meet the preset standard based on the pressure difference of the compressed exhaust gas and to determine whether the liquefaction and purification of the exhaust gas meets the preset standard based on the dielectric matching degree of the liquefied carbon dioxide, wherein the reasons include leakage in the transportation of the compressed exhaust gas or failure of the compressor resulting in blockage of the second flow channel.

2. The skid-mounted device for dry ice tail gas recovery according to claim 1, characterized in that: The heat exchanger has a first flow channel and a second flow channel inside. The first flow channel is connected to the exhaust gas input port and the exhaust gas output port respectively, and the second flow channel is connected to the compressed exhaust gas input port and the compressed exhaust gas output port respectively.

3. The skid-mounted device for dry ice tail gas recovery according to claim 2, characterized in that: The control module determines whether the heat exchange compression of the exhaust gas meets the preset standard according to the temperature variance of the heat exchanger, wherein: If the temperature variance is less than the first preset temperature variance, it is determined that the heat exchange compression of the tail gas meets the preset standard, and the tail gas meeting the preset standard is transported to the liquefaction purification component; If the temperature variance is greater than or equal to the first preset temperature variance and less than the second preset temperature variance, it is determined that the heat exchange compression of the exhaust gas does not meet the preset standard, and a second determination is made based on the thermal response index of the heat exchanger whether the heat exchange compression of the exhaust gas meets the preset standard; If the temperature variance is greater than or equal to the second preset temperature variance, it is determined that the heat exchange compression of the exhaust gas does not meet the preset standard, and the reason why the heat exchange compression of the exhaust gas does not meet the preset standard is determined according to the pressure difference of the compressed exhaust gas; The temperature variance is determined by the temperature collected by the temperature collection unit.

4. The skid-mounted device for dry ice tail gas recovery according to claim 3, characterized in that: The control module determines whether the heat exchange compression of the exhaust gas meets the preset standard based on the thermal response index of the heat exchanger. If the thermal response index is less than the preset thermal response index, it is determined that the heat exchange compression of the tail gas meets the preset standard, and the tail gas meeting the preset standard is transported to the liquefaction purification component; If the thermal response index is greater than or equal to the preset thermal response index, it is determined that the heat exchange compression of the exhaust gas does not meet the preset standard, and the speed of the compressor is increased according to the difference between the preset thermal response index and the thermal response index.

5. The skid-mounted device for recovering dry ice tail gas according to claim 4, characterized in that: The thermal response index is the ratio of the response time required for the center temperature of the heat exchanger to reach a steady state to the preset response time when the flow rate of the dry ice exhaust gas entering the first flow channel exceeds the preset discharge flow rate.

6. The skid-mounted device for recovering dry ice tail gas according to claim 4 or 5, characterized in that: The control module is provided with several speed regulating modes for increasing the speed of the compressor, and each speed regulating mode increases the speed of the compressor by a different amount.

7. The skid-mounted device for dry ice tail gas recovery according to claim 6, characterized in that: The control module determines the reason why the heat exchange compression of the exhaust gas does not meet the preset standard according to the pressure difference of the compressed exhaust gas, wherein: If the pressure difference is less than the preset pressure difference, it is determined that the reason why the heat exchange compression of the exhaust gas does not meet the preset standard is that the transmission of the compressed exhaust gas leaks; If the pressure difference is greater than or equal to the preset pressure difference, it is determined that the reason why the heat exchange compression of the exhaust gas does not meet the preset standard is that the compressor fails and causes the second flow channel to be blocked.

8. The skid-mounted device for dry ice tail gas recovery according to claim 7, characterized in that: The control module determines whether the liquefaction and purification of tail gas meets the preset standard according to the dielectric matching degree of liquefied carbon dioxide, wherein: If the dielectric matching degree is less than the preset matching degree, it is determined that the liquefaction and purification of the tail gas does not meet the preset standard, and the gas-liquid separation time of the gas-liquid separator is increased according to the difference between the preset matching degree and the dielectric matching degree; If the dielectric matching degree is greater than or equal to the preset matching degree, it is determined that the liquefaction and purification of the tail gas meets the preset standard.

9. The skid-mounted device for dry ice tail gas recovery according to claim 8, characterized in that: The dielectric matching degree is the ratio between the dielectric constant of liquid carbon dioxide and a preset dielectric constant.

10. The skid-mounted device for dry ice tail gas recovery according to claim 9, characterized in that: The increase in the gas-liquid separation time of the gas-liquid separator is positively correlated with the matching difference, wherein the matching difference is the difference between the preset matching degree and the dielectric matching degree.

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