Cold-carrying circulation VOCs low-temperature condensation recovery system

Abstract

The invention relates to the technical field of VOCs condensation recovery, in particular to a cold-carrying circulation VOCs low-temperature condensation recovery system which comprises a mixed working medium refrigeration circulation loop and a VOCs condensation pipeline. The mixed working medium refrigeration circulation loop and the VOCs condensation pipeline transfer cold energy through the cold-carrying circulation loop, and the cold-carrying circulation loop comprises a cold-carrying working medium circulation driver (201) and a cold-carrying working medium flow channel; the cold-carrying working medium flow channel is sequentially connected with a mixed working medium heat regenerator (103) in the mixed working medium refrigeration circulation loop, a VOCs cooling heat exchanger (301) in the VOCs condensation pipeline and a cold-carrying working medium circulation driver (201); due to the arrangement of the cold carrying circulation loop, cold energy is adjusted more gently in the whole process, the adjusting range is wider, and VOCs to be recycled which are large in flow and unstable in working condition can be better condensed; in addition, the VOCs cooling heat exchanger arranged in the independent loop can be arranged according to the actual VOCs amount to be recycled, the design complexity is reduced, and meanwhile the system size is smaller.

Description

Technical Field

[0001] The present disclosure relates to the technical field of VOCs condensation recovery, and in particular to a cold-carrying cycle VOCs low-temperature condensation recovery system. Background Art

[0002] VOCs, or volatile organic compounds, are harmful to the environment and human body. They mainly come from coal chemical industry, petrochemical industry, fuel coating manufacturing, solvent manufacturing and use, etc. The recovery of VOCs can avoid its pollution to the environment and also has certain economic value.

[0003] At present, the condensation method is often used to condense and recover VOCs, among which two-stage and three-stage cascade refrigeration or liquid nitrogen refrigeration are more commonly used refrigeration methods. However, for cascade refrigeration, the multi-stage setting makes the entire condensation recovery equipment complex and costly, while the cold energy quality generated during the liquid nitrogen refrigeration process is high. For VOCs with relatively high recovery temperatures, the supply and demand do not match, resulting in serious waste; in addition, the inter-wall heat recovery refrigeration technology represented by the mixed working fluid refrigeration technology can distribute the gas load in its heat recovery heat exchanger to reduce the irreversible loss caused by the large heat exchange temperature difference, which has certain positive significance. However, in the actual processing process, VOCs have low pressure and large flow, and the operating conditions fluctuate violently and unstable. When VOCs directly exchange heat with the mixed working fluid, the heat exchanger requires a large number of heat exchange channels to meet the demand, resulting in the entire heat exchange equipment having a complex structure and large size. At the same time, the sensitivity, timeliness and range of adjustment cannot be effectively guaranteed. Summary of the invention

[0004] In order to solve the above technical problems or partially solve the above technical problems, the present disclosure provides a refrigeration cycle VOCs low-temperature condensation recovery system.

[0005] The present disclosure provides a cold-carrying cycle VOCs low-temperature condensation recovery system, comprising a mixed working fluid refrigeration cycle loop and a VOCs condensation pipeline;

[0006] The mixed working medium refrigeration cycle and the VOCs condensation pipeline transfer cold energy through a cold-carrying circulation loop, and the cold-carrying circulation loop includes a cold-carrying working medium circulation driver and a cold-carrying working medium flow channel;

[0007] The cooling medium flow channel is connected in sequence to the mixed medium heat regenerator in the mixed medium refrigeration cycle, the VOCs cooling heat exchanger in the VOCs condensation pipeline, and the cooling medium circulation driver;

[0008] Optionally, the mixed working fluid refrigeration cycle loop further includes a mixed working fluid compressor, a mixed working fluid aftercooler, and a mixed working fluid throttling element;

[0009] The mixed working medium regenerator is provided with a mixed working medium flow channel a, a mixed working medium flow channel b and a mixed working medium flow channel c inside;

[0010] The mixed working fluid compressor, the mixed working fluid aftercooler, the mixed working fluid flow channel a, the mixed working fluid throttling element, and the mixed working fluid flow channel b are connected in sequence through pipelines;

[0011] The VOCs condensation pipeline also includes a separator and an air extractor;

[0012] The VOCs cooling heat exchanger is provided with cooling channels a, b and c inside;

[0013] The cooling channel b, the exhaust channel of the separator, the cooling channel c, and the air extractor are connected in sequence through pipelines;

[0014] The cooling medium flow channel is sequentially connected to the mixed medium flow channel c, the cooling flow channel a, and the cooling medium circulation driver.

[0015] Optionally, the separator is a distillation tower or a fractional condensation separator, and a condensation component is provided inside the distillation tower or the fractional condensation separator, and a channel for circulating cold medium in the condensation component is connected to the cold-carrying circulation loop.

[0016] Optionally, it also includes a cooling medium storage module, which is connected to the circuit where the cooling medium flow channel is located and is used to adjust the degree of cold energy transfer of the cooling circulation circuit.

[0017] Optionally, the mixed working fluid refrigeration cycle circuit includes a first mixed working fluid refrigeration cycle circuit and a second mixed working fluid refrigeration cycle circuit;

[0018] The mixed working fluid regenerator comprises a first mixed working fluid regenerator and a second mixed working fluid regenerator;

[0019] The first mixed working medium refrigeration cycle circuit also includes a first mixed working medium compressor, a first mixed working medium aftercooler, and a first mixed working medium throttling element;

[0020] The first mixed working medium regenerator is provided with a first mixed working medium flow channel a, a first mixed working medium flow channel b and a first mixed working medium flow channel c inside;

[0021] The first mixed working fluid compressor, the first mixed working fluid aftercooler, the first mixed working fluid flow channel a, the first mixed working fluid throttling element, and the first mixed working fluid flow channel b are connected in sequence through pipelines, and the first mixed working fluid refrigeration cycle circuit is used to provide cold energy for cooling VOCs with relatively low cooling temperature;

[0022] The second mixed working medium refrigeration cycle circuit also includes a second mixed working medium compressor, a second mixed working medium aftercooler, and a second mixed working medium throttling element;

[0023] The second mixed working medium regenerator is provided with a second mixed working medium flow channel a, a second mixed working medium flow channel b and a second mixed working medium flow channel c;

[0024] The second mixed working fluid compressor, the second mixed working fluid aftercooler, the second mixed working fluid flow channel a, the second mixed working fluid throttling element, and the second mixed working fluid flow channel b are connected in sequence through pipelines, and the second mixed working fluid refrigeration cycle circuit is used to provide cold energy for cooling VOCs with relatively high cooling temperature;

[0025] The VOCs condensation pipeline is a total VOCs condensation pipeline, and the total VOCs condensation pipeline also includes a first separator, a second separator, and an air extractor; the VOCs cooling heat exchanger includes a first VOCs cooling heat exchanger and a second VOCs cooling heat exchanger;

[0026] The first VOCs cooling heat exchanger is provided with a first cooling channel a, a first cooling channel b and a first cooling channel c inside;

[0027] The second VOCs cooling heat exchanger is provided with a second cooling channel a, a second cooling channel b and a second cooling channel c inside;

[0028] The second cooling channel b, the exhaust channel of the second separator, the first cooling channel b, the exhaust channel of the first separator, the first cooling channel c, the second cooling channel c, and the air extractor are connected in sequence through pipelines;

[0029] The first separator is used to separate lighter hydrocarbons, and the second separator is used to separate heavier hydrocarbons;

[0030] The outlet of the cooling medium circulation driver is connected to the inlet of the first mixed medium flow channel c and the inlet of the second mixed medium flow channel c respectively through the cooling medium flow channel, the outlet of the first mixed medium flow channel c is connected to the inlet of the first cooling flow channel a through the cooling medium flow channel, the outlet of the second mixed medium flow channel c and the outlet of the first cooling flow channel a are both connected to the inlet of the second cooling flow channel a through the cooling medium flow channel, and the outlet of the second cooling flow channel a is connected to the inlet of the cooling medium circulation driver;

[0031] The first separator is a first distillation tower or a first fractional condensation separator, wherein a first condensation assembly is provided inside the first distillation tower or the first fractional condensation separator, and a channel for circulating a cold medium in the first condensation assembly is connected to the loop of the cold medium flow channel;

[0032] The second separator is a second distillation tower or a second condensation separator, and a second condensation component is provided inside the second distillation tower or the second condensation separator. The channel for circulating the cold medium in the second condensation component is connected to the loop of the cold medium flow channel.

[0033] Optionally, the first condensing component is connected between the first mixed medium flow channel c and the first cooling flow channel a;

[0034] The second condensing assembly is connected between the second mixed medium flow channel c and the second cooling flow channel a.

[0035] Optionally, it further includes a first cooling medium storage module and a second cooling medium storage module;

[0036] The first cooling medium storage module is connected to the cooling medium flow channel between the first mixed medium flow channel c and the first condensing component; the second cooling medium storage module is connected to the cooling medium flow channel between the second mixed medium flow channel c and the second condensing component;

[0037] The first cooling medium storage module and the second cooling medium storage module are both used to adjust the degree of cold energy transfer of the cooling circulation loop.

[0038] Optionally, a pre-cooling heat exchanger is also included;

[0039] The precooling heat exchanger is provided with a precooling channel a, a precooling channel b, a precooling channel c and a precooling channel d;

[0040] The inlet of the precooling channel a is connected to the outlet of the first mixed working medium aftercooler, and the outlet of the precooling channel a is connected to the inlet of the first mixed working medium channel a;

[0041] The inlet of the precooling flow channel b is connected to the outlet of the first mixed working medium flow channel b, and the outlet of the precooling flow channel b is connected to the inlet of the first mixed working medium compressor;

[0042] The inlet of the precooling channel c is connected to the outlet of the second mixed working medium aftercooler, and the outlet of the precooling channel c is connected to the inlet of the second mixed working medium channel a;

[0043] The inlet of the precooling flow channel d is connected to the outlet of the second mixed working medium flow channel b, and the outlet of the precooling flow channel d is connected to the inlet of the second mixed working medium compressor.

[0044] Optionally, the cooling medium circulation driver is a circulation pump;

[0045] or,

[0046] The cooling medium circulation driver is a cooling medium compressor and a cooling medium aftercooler.

[0047] Optionally, the cooling medium in the cooling circulation loop is any one of propane, propylene, cyclopropane, isobutane, n-butane, 1-butene, isobutylene, isopentane, n-pentane, cyclopentane, n-hexane, ethane, ethylene, methane, nitrogen, argon, helium, neon, ammonia, air, R14, R23, R41, R116, R32, R125, R143a, R143, R22, R134a, R152a, R161, R218, R1234yf, R1234ze(E), fluorinated liquid, methanol, ethanol, and ethylene glycol, or a mixture of several of them.

[0048] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0049] The present invention provides a cold-carrying cycle VOCs low-temperature condensation recovery system. Under the action of the cold-carrying cycle loop, the loop where the mixed working fluid heat regenerator is located and the loop directly involved in VOCs recovery are independent of each other and maintain the transfer of cold energy at the same time. At the same time, the setting of the cold-carrying cycle loop makes the regulation of cold energy in the whole process smoother and the regulation range wider, and can better condense the VOCs to be recovered with large flow and unstable working conditions; in addition, the VOCs cooling heat exchanger set in the independent loop can be set according to the actual amount of VOCs to be recovered, which greatly reduces the complexity of the design, and the system volume is smaller and less limited by the environment; and because there is a cold-carrying loop in the middle for adjustment, the loop where the VOCs cooling heat exchanger is located under the independent setting can more flexibly respond to the actual amount of VOCs to be recovered to make pipeline changes and selections, without having to worry about whether the changes brought about directly affect the efficiency of heat exchange, thereby improving the adaptability to the specific situation of the VOCs to be recovered. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0052] Figure 1 This is a schematic structural diagram of the refrigeration cycle VOCs low-temperature condensation recovery system disclosed in the present invention;

[0053] Figure 2 This is a schematic structural diagram of an embodiment of providing a cooling medium storage module in the cooling cycle VOCs low-temperature condensation recovery system disclosed in the present invention;

[0054] Figure 3 This is a schematic structural diagram of an embodiment in which the separator in the cold-carrying cycle VOCs low-temperature condensation recovery system disclosed in the present invention is a distillation tower;

[0055] Figure 4 It is a schematic structural diagram of an embodiment of a case where the separator in the cold-carrying cycle VOCs low-temperature condensation recovery system disclosed in the present invention is a condensation separator;

[0056] Figure 5 This is a schematic structural diagram of an embodiment of a case where the cooling medium circulation driver in the cooling medium circulation VOCs low-temperature condensation recovery system disclosed in the present invention is a cooling medium compressor and a cooling medium aftercooler;

[0057] Figure 6 This is a schematic structural diagram of an embodiment of the cold-carrying cycle VOCs low-temperature condensation recovery system disclosed in the present invention for different condensation temperatures of VOCs.

[0058] Among them, 101, mixed working fluid compressor; 102, mixed working fluid aftercooler; 103, mixed working fluid regenerator; 1030, mixed working fluid flow channel a; 1031, mixed working fluid flow channel b; 1032, mixed working fluid flow channel c; 104, mixed working fluid throttling element; 111, first mixed working fluid compressor; 112, first mixed working fluid aftercooler; 113, precooling heat exchanger; 1130, precooling flow channel a; 1131, precooling flow channel b; 1132, precooling flow channel c; 1133, Precooling flow channel d; 114, first mixed working medium regenerator; 1140, first mixed working medium flow channel a; 1141, first mixed working medium flow channel b; 1142, first mixed working medium flow channel c; 115, first mixed working medium throttling element; 121, second mixed working medium compressor; 122, second mixed working medium aftercooler; 123, second mixed working medium regenerator; 1230, second mixed working medium flow channel a; 1231, second mixed working medium flow channel b; 1232, second mixed working medium flow channel c; 12 4. Second mixed working fluid throttling element; 201. Cooling working fluid circulation driver; 202. Cooling working fluid storage module; 203. Condensation assembly; 212. Second cooling working fluid storage module; 213. Second condensation assembly; 214. First cooling working fluid storage module; 215. First condensation assembly; 216. Pipeline distributor; 217. Pipeline mixer; 221. Cooling working fluid compressor; 222. Cooling working fluid aftercooler; 301. VOCs cooling heat exchanger; 3010. Cooling channel a; 3011, cooling channel b; 3012, cooling channel c; 302, separator; 303, vacuum fan; 311, second VOCs cooling heat exchanger; 3110, second cooling channel a; 3111, second cooling channel b; 3112, second cooling channel c; 312, second separator; 313, first VOCs cooling heat exchanger; 3130, first cooling channel a; 3131, first cooling channel b; 3132, first cooling channel c; 314, first separator. DETAILED DESCRIPTION

[0059] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0060] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0062] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0063] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0064] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0065] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0066] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0067] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0068] Reference Figure 1 As shown, a cold-carrying cycle VOCs low-temperature condensation recovery system provided in this embodiment includes a mixed working fluid refrigeration cycle loop and a VOCs condensation pipeline; the mixed working fluid refrigeration cycle loop and the VOCs condensation pipeline transfer cold energy through the cold-carrying cycle loop, and the cold-carrying cycle loop includes a cold-carrying working fluid circulation driver 201 and a cold-carrying working fluid flow channel; under the action of the cold-carrying cycle loop, the mixed working fluid refrigeration cycle loop and the VOCs condensation pipeline are independent of each other and maintain the transfer of cold energy at the same time. At the same time, the setting of the cold-carrying cycle makes the regulation of cold energy in the whole process smoother and the regulation range wider, which is suitable for large flow rates. And for VOCs to be recovered with unstable working conditions, they can be better condensed; in addition, the mixed refrigerant refrigeration cycle circuit with independent loop setting can be set according to the actual amount of VOCs to be recovered, which greatly reduces the complexity of the design, while occupying less space and being less limited by the environment; and because there is a cold-carrying loop in the middle for adjustment, the VOCs condensation pipeline under the independent setting can more flexibly respond to the actual amount of VOCs to be recovered and make pipeline adjustments and selections. There is no need to worry about whether the changes brought about directly affect the efficiency of heat exchange, which improves the adaptability to VOCs to be recovered.

[0069] Specifically, the cooling medium flow channel is connected in sequence to the mixed medium heat regenerator 103 in the mixed medium refrigeration cycle, the VOCs cooling heat exchanger 301 in the VOCs condensation pipeline, and the cooling medium circulation driver 201 to form a closed-loop cooling medium circulation loop to continuously transfer cold energy.

[0070] In some embodiments, the mixed working fluid refrigeration cycle loop also includes a mixed working fluid compressor 101, a mixed working fluid aftercooler 102, and a mixed working fluid throttling element 104; the mixed working fluid regenerator 103 is internally provided with a mixed working fluid flow channel a1030, a mixed working fluid flow channel b1031, and a mixed working fluid flow channel c1032.

[0071] Specifically, the mixed working fluid compressor 101, the mixed working fluid aftercooler 102, the mixed working fluid flow channel a1030, the mixed working fluid throttling element 104, and the mixed working fluid flow channel b1031 are connected in sequence through pipelines. In the actual process, the mixed working fluid is compressed in the mixed working fluid compressor 101, and the temperature rises after compression. Then, it passes through the mixed working fluid aftercooler 102, and is cooled to a certain extent in the mixed working fluid aftercooler 102. After cooling, it enters the mixed working fluid flow channel a1030 to participate in heat exchange and cooling, and then passes through the mixed working fluid throttling element 104 to cool down and reduce the pressure, and then re-enters the mixed working fluid compressor 101 through the mixed working fluid flow channel b1031 for circulation.

[0072] It should be noted that heat exchange can be carried out between the mixed working fluid flow channel a1030 and the mixed working fluid flow channel b1031. After passing through the mixed working fluid throttling element 104, the temperature of the mixed working fluid is further reduced, thereby synchronously reducing the temperature of the mixed working fluid flowing in the mixed working fluid flow channel a1030, realizing positive feedback of refrigeration and ensuring the efficiency of refrigeration.

[0073] Specifically, the VOCs condensation pipeline also includes a separator 302 and an exhaust fan 303; the interior of the VOCs cooling heat exchanger 301 is provided with a cooling channel a3010, a cooling channel b3011 and a cooling channel c3012; the cooling channel b3011, the exhaust channel of the separator 302, the cooling channel c3012, and the exhaust fan 303 are connected in sequence through pipelines; the VOCs feed enters the cooling channel b3011, is cooled by the cold energy transmitted by the cold circulation loop, and then enters the separator 302 to separate the condensed liquid hydrocarbons, and the clean air will be discharged through the exhaust channel of the separator 302, and at the same time enter the cooling channel c3012 in the VOCs cooling heat exchanger 301. At this time, the air temperature at the separation point of the separator 302 is still at a relatively low level. When it passes through the cooling channel c3012, it can also cool the VOCs feed in the cooling channel b3011, realizing positive feedback and ensuring the cooling effect.

[0074] The cooling medium flow channel in the cooling circulation loop is connected to the mixed medium flow channel c1032, the cooling flow channel a3010, and the cooling medium circulation driver 201 in sequence. The cooling medium in the cooling medium circulation loop exchanges heat with the mixed medium in the mixed medium flow channel b1031 in the mixed medium flow channel c1032 to achieve cooling of the cooling medium itself; then it enters the cooling flow channel a3010 in the VOCs cooling heat exchanger 301 to exchange heat with the VOCs to be recovered in the cooling flow channel b3011 to achieve cooling of the VOCs; the setting of the cooling circulation loop is equivalent to adding an additional adjustment loop, which increases the range of adjustment and also increases the smoothness of the adjustment.

[0075] refer to Figure 3and Figure 4 As shown, in some further embodiments, the separator 302 is a distillation tower or a condenser, and a condensation component 203 is provided inside the distillation tower or the condenser. The channel for circulating the refrigerant in the condensation component 203 is connected to the cold-carrying circulation loop; the refrigerant in the cold-carrying medium flow channel, in addition to directly participating in heat exchange in the VOCs condensation pipeline, will also increase the condensation effect through the channel for circulating the refrigerant in the condensation component 203, thereby better promoting the separation of gases and hydrocarbons in the VOCs.

[0076] In addition, the condensing component 203 may be in the form of tube arrays, coils, fin tubes, microchannels, or other forms.

[0077] Furthermore, in some embodiments, when the separator 302 is a distillation tower, the condensation component 203 can be set at the top of the distillation tower, or it can be set in the middle of the distillation tower. Of course, in some other cases, such as when the flow rate is large, multiple condensation components 203 can also be set, and they can be set at the top and the middle of the distillation tower at the same time to better ensure the efficiency of gas-liquid separation and reduce the residual hydrocarbons in the VOCs to be recovered.

[0078] refer to Figure 2 As shown, in some further embodiments, it also includes a cooling medium storage module 202, which is connected to the loop where the cooling medium flow channel is located, and is used to adjust the degree of cold energy transfer of the cooling circulation loop; in the process of VOCs condensation recovery, the recovery temperatures of different hydrocarbons are different. In order to adjust the temperature more targetedly, a cooling medium storage module 202 is set in the cooling circulation loop. The cooling medium storage module 202 generally includes a storage container and a corresponding control valve group. When the required VOCs cooling temperature does not need to be lower, the cooling medium in the cooling circulation loop can be circulated to a part of the storage container through the adjustable control valve group, thereby appropriately reducing the degree of cold energy transfer of the cooling circulation loop to accurately adapt to the needs and avoid waste; and when the required VOCs cooling temperature needs to be lower, the cooling medium in the storage container can be released by adjusting the control valve group, thereby increasing the degree of cold energy transfer of the cooling circulation loop, adapting to the needs, and ensuring normal cooling.

[0079] It is conceivable that, in some further embodiments, a pipeline for injecting a cooling medium may be provided on the storage container, and when the required cooling temperature is low, the cooling medium may be injected into the cooling circulation loop to ensure normal cooling.

[0080] Please refer to Figure 6 As shown, the mixed working medium refrigeration cycle circuit includes a first mixed working medium refrigeration cycle circuit and a second mixed working medium refrigeration cycle circuit.

[0081] The mixed working medium heat regenerator includes a first mixed working medium heat regenerator 114 and a second mixed working medium heat regenerator 123 .

[0082] The first mixed working medium refrigeration cycle loop also includes a first mixed working medium compressor 111, a first mixed working medium aftercooler 112, and a first mixed working medium throttling element 115; the first mixed working medium regenerator 114 is internally provided with a first mixed working medium flow channel a1140, a first mixed working medium flow channel b1141 and a first mixed working medium flow channel c1142.

[0083] The first mixed working fluid compressor 111, the first mixed working fluid aftercooler 112, the first mixed working fluid flow channel a1140, the first mixed working fluid throttling element 115, and the first mixed working fluid flow channel b1141 are connected in sequence through pipelines, and the first mixed working fluid refrigeration cycle loop is used to provide cold energy for VOCs with relatively low cooling temperature; the first mixed working fluid refrigeration cycle loop is mainly used to separate lighter hydrocarbons.

[0084] The second mixed working medium refrigeration cycle loop also includes a second mixed working medium compressor 121, a second mixed working medium aftercooler 122, and a second mixed working medium throttling element 124; the second mixed working medium regenerator 123 is provided with a second mixed working medium flow channel a1230, a second mixed working medium flow channel b1231 and a second mixed working medium flow channel c1232.

[0085] The second mixed working fluid compressor 121, the second mixed working fluid aftercooler 122, the second mixed working fluid flow channel a1230, the second mixed working fluid throttling element 124, and the second mixed working fluid flow channel b1231 are connected in sequence through pipelines, and the second mixed working fluid refrigeration cycle loop is used to provide cold energy for VOCs with relatively high cooling temperature; the second mixed working fluid refrigeration cycle loop is mainly used to separate relatively high hydrocarbons.

[0086] The VOCs condensation pipeline is a total VOCs condensation pipeline, and the total VOCs condensation pipeline includes a first separator 314 , a second separator 312 , and an exhaust fan 303 ; the VOCs cooling heat exchanger 301 includes a first VOCs cooling heat exchanger 313 and a second VOCs cooling heat exchanger 311 .

[0087] In addition, the first VOCs cooling heat exchanger 313 is provided with a first cooling channel a3130, a first cooling channel b3131 and a first cooling channel c3132; the second VOCs cooling heat exchanger 311 is provided with a second cooling channel a3110, a second cooling channel b3111 and a second cooling channel c3112.

[0088] The second cooling channel b3111, the exhaust channel of the second separator 312, the first cooling channel b3131, the exhaust channel of the first separator 314, the first cooling channel c3132, the second cooling channel c3112, and the vacuum fan 303 are connected in sequence through pipelines; corresponding to the above-mentioned first mixed working fluid refrigeration cycle and the second mixed co-media refrigeration cycle respectively, the first separator 314 is used to separate lighter hydrocarbons, and the second separator 312 is used to separate heavier hydrocarbons.

[0089] The outlet of the cooling medium circulation driver 201 is connected to the inlet of the first mixed working medium flow channel c1142 and the inlet of the second mixed working medium flow channel c1232 respectively through the cooling medium flow channel; the outlet of the first mixed working medium flow channel c1142 is connected to the inlet of the first cooling flow channel a3130 through the cooling medium flow channel; the outlet of the second mixed working medium flow channel c1232 and the outlet of the first cooling flow channel a3130 are both connected to the inlet of the second cooling flow channel a3110 through the cooling medium flow channel; the outlet of the second cooling flow channel a3110 is connected to the inlet of the cooling medium circulation driver 201.

[0090] Among them, the cooling medium passing through the second mixed working medium flow channel c1232 is cooled to -120℃~-10℃, and the cooling medium passing through the first mixed working medium flow channel c1142 is cooled to -180℃~-120℃; the VOCs passing through the second cooling flow channel a3110 are cooled to -115℃~-0℃, and the VOCs passing through the first cooling flow channel a3130 are cooled to -120℃~-10℃.

[0091] By setting a first mixed working fluid refrigeration cycle loop and a second mixed working fluid refrigeration cycle loop, the original cold energy supply loop is improved into two supply loops at different temperature steps. When facing heavier hydrocarbons and lighter hydrocarbons in VOCs, cold energy can be supplied respectively. For example, when separating lighter hydrocarbons, the required cooling temperature is lower. At this time, the refrigeration of the first mixed working fluid refrigeration cycle loop can be increased to meet the lower temperature requirement. When separating heavier hydrocarbons, the required cooling temperature is higher. At this time, the refrigeration of the second mixed working fluid refrigeration cycle loop can be reduced to meet the higher temperature requirement. In this mode, the supply and demand are appropriate, and there will be no waste of cold energy. At the same time, the cold energy requirements of different VOCs can be met, and finally the condensation recovery of VOCs is realized scientifically and efficiently.

[0092] In addition, in some embodiments, the cooling medium after passing through the cooling medium circulation driver 201 can enter the first mixed medium flow channel c1142 and the second mixed medium flow channel c1232 through the pipeline distributor 216 respectively.

[0093] In some other embodiments, the cooling medium flowing out of the first cooling channel a3130 and the cooling medium flowing out of the second mixed medium channel c1232 can be combined through the pipeline mixer 217 and then enter the second cooling channel a3110 to achieve sequencing.

[0094] It should be noted that after the refrigerant passing through the first cooling channel a3130 exchanges heat with the first cooling channel b3131, the temperature of the refrigerant flowing therein will be higher than before. At this time, it will participate in the heat exchange circuit for condensing and recovering VOCs with higher required temperatures through the pipeline mixer 217, that is, the second cooling channel a3110, thereby realizing heat exchange cooling of VOCs with different temperature requirements in turn, and at the same time making full use of the cold energy provided by the refrigerant, avoiding waste while ensuring supply and demand.

[0095] In some other embodiments, the first separator 314 is a first distillation tower or a first condensation separator, and a first condensation component 215 is provided inside the first distillation tower or the first condensation separator, and a channel for circulating cold medium in the first condensation component 215 is connected to a cold circulation loop; the second separator 312 is a second distillation tower or a second condensation separator, and a second condensation component 213 is provided inside the second distillation tower or the second condensation separator, and a channel for circulating cold medium in the second condensation component 213 is connected to a circuit of a cold medium flow channel. After the cold medium flows through the first condensation component 215 and the second condensation component 213, it can ensure that the gas-liquid separation in the first separator 314 and the second separator 312 is more thorough, so as to minimize the hydrocarbons in the gas and ensure the recovery effect.

[0096] In some other embodiments, the first condensing component 215 is connected between the first mixed working fluid flow channel c1142 and the first cooling flow channel a3130; the second condensing component 213 is connected between the second mixed working fluid flow channel c1232 and the second cooling flow channel a3110.

[0097] In some further embodiments, a first cooling medium storage module 214 and a second cooling medium storage module 212 are also included: the first cooling medium storage module 214 is connected to the cooling medium flow channel between the first mixed medium flow channel c1142 and the first condensing component 215; the second cooling medium storage module 212 is connected to the cooling medium flow channel between the second mixed medium flow channel c1232 and the second condensing component 213; the first cooling medium storage module 214 and the second cooling medium storage module 212 are both used to adjust the degree of cold energy transfer of the cooling circulation loop; the first cooling medium storage module 214 and the second cooling medium storage module 212 can both be storage containers and corresponding control valve groups to adjust the degree of cold energy transfer of the loop when responding to different temperature requirements; at the same time, it should be pointed out that when more than two cooling medium storage modules 202 are arranged in the entire cooling circulation loop, the degree of cold energy transfer of the cooling circulation loop can be controlled more accurately.

[0098] In some further embodiments, a precooling heat exchanger 113 is further included; a precooling flow channel a1130, a precooling flow channel b1131, a precooling flow channel c1132 and a precooling flow channel d1133 are arranged inside the precooling heat exchanger 113; the inlet of the precooling flow channel a1130 is connected to the outlet of the first mixed working medium aftercooler 112, and the outlet of the precooling flow channel a1130 is connected to the inlet of the first mixed working medium flow channel a1140; the inlet of the precooling flow channel b1131 is connected to the first mixed working medium flow channel b114 1, the outlet of the precooling channel b1131 is connected to the inlet of the first mixed working fluid compressor 111; the inlet of the precooling channel c1132 is connected to the outlet of the second mixed working fluid aftercooler 122, and the outlet of the precooling channel c1132 is connected to the inlet of the second mixed working fluid channel a1230; the inlet of the precooling channel d1133 is connected to the outlet of the second mixed working fluid channel b1231, and the outlet of the precooling channel d1133 is connected to the inlet of the second mixed working fluid compressor 121.

[0099] The precooling heat exchanger 113 is used to reduce the large temperature heat exchange difference and avoid the irreversible loss of cold energy. Specifically, after the first mixed working fluid in the first mixed working fluid refrigeration cycle passes through the first mixed working fluid compressor 111 and the first mixed working fluid aftercooler 112, it enters the precooling flow channel a1130 and is cooled to the precooling temperature (generally -20°C to 10°C), and then passes through the first mixed working fluid flow channel a1140, and then is cooled and depressurized by the first mixed working fluid throttling element 115, and then flows through the first mixed working fluid flow channel b1141, the precooling flow channel b1131, and the first mixed working fluid compressor 111 in sequence to realize the cycle. It should be noted that positive feedback cooling heat exchange is realized between the precooling flow channel a1130, the precooling flow channel b1131, and between the first mixed working fluid flow channel a1140 and the first mixed working fluid flow channel b1141 to ensure the cooling effect.

[0100] The flow process of the second mixed working fluid is the same as that of the first mixed working fluid, and will not be repeated here.

[0101] refer to Figure 5 As shown, in some further embodiments, the cooling working fluid circulation driver 201 is a circulation pump; or, the cooling working fluid circulation driver 201 is a cooling working fluid compressor 221 and a cooling working fluid aftercooler 222. The temperature of the working fluid after compression will increase to a certain extent, so the cooling working fluid compressor 221 and the cooling working fluid aftercooler 222 are arranged in combination to act as the cooling working fluid circulation driver 201.

[0102] It should be noted that the above-mentioned mixed working fluid, the first mixed working fluid, and the second mixed working fluid can be a mixture of several of helium, neon, nitrogen, argon, methane, ethane, ethylene, propane, propylene, cyclopropane, isobutane, n-butane, 1-butene, isobutene, isopentane, n-pentane, cyclopentane, n-hexane, R14, R23, R41, R116, R32, R125, R143a, R143, R22, R134a, R152a, R161, R218, R1234yf, and R1234ze(E); and the carrier The refrigerant can be one of propane, propylene, cyclopropane, isobutane, n-butane, 1-butene, isobutene, isopentane, n-pentane, cyclopentane, n-hexane, ethane, ethylene, methane, nitrogen, argon, helium, neon, ammonia, air, R14, R23, R41, R116, R32, R125, R143a, R143, R22, R134a, R152a, R161, R218, R1234yf, R1234ze(E), fluorinated liquid, methanol, ethanol, ethylene glycol, or a mixture of several of them.

[0103] The specific implementation methods and implementation principles are the same as those of the above-mentioned embodiments, and the embodiments that can bring the same or similar technical effects will not be described here one by one. For details, please refer to the description of the above-mentioned cold cycle VOCs low-temperature condensation recovery system embodiment.

[0104] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cold cycle VOCs low temperature condensation recovery system, characterized in that: Including mixed working fluid refrigeration cycle loop and VOCs condensation pipeline; The mixed working medium refrigeration circulation loop and the VOCs condensation pipeline transfer cold energy via a cold-carrying circulation loop, wherein the cold-carrying circulation loop comprises a cold-carrying working medium circulation driver (201) and a cold-carrying working medium flow channel; The cooling medium flow channel is sequentially connected to the mixed medium heat regenerator (103) in the mixed medium refrigeration cycle, the VOCs cooling heat exchanger (301) in the VOCs condensation pipeline, and the cooling medium circulation driver (201).

2. The cold cycle VOCs low temperature condensation recovery system according to claim 1 is characterized in that: The mixed working fluid refrigeration cycle loop also includes a mixed working fluid compressor (101), a mixed working fluid aftercooler (102), and a mixed working fluid throttling element (104); The mixed working medium heat regenerator (103) is provided with a mixed working medium flow channel a (1030), a mixed working medium flow channel b (1031) and a mixed working medium flow channel c (1032) inside; The mixed working fluid compressor (101), the mixed working fluid aftercooler (102), the mixed working fluid flow channel a (1030), the mixed working fluid throttling element (104), and the mixed working fluid flow channel b (1031) are connected in sequence through pipelines; The VOCs condensation pipeline further includes a separator (302) and an air extractor (303); The VOCs cooling heat exchanger (301) is provided with a cooling channel a (3010), a cooling channel b (3011) and a cooling channel c (3012) inside; The cooling channel b (3011), the exhaust channel of the separator (302), the cooling channel c (3012), and the air extractor (303) are connected in sequence through pipelines; The cooling medium flow channel is sequentially connected to the mixed medium flow channel c (1032), the cooling flow channel a (3010), and the cooling medium circulation driver (201).

3. The cold cycle VOCs low temperature condensation recovery system according to claim 2 is characterized in that: The separator (302) is a distillation tower or a fractional condensation separator, and a condensation component (203) is provided inside the distillation tower or the fractional condensation separator. The channel for circulating cold medium in the condensation component (203) is connected to the cold-carrying circulation loop.

4. The refrigeration cycle VOCs low temperature condensation recovery system according to any one of claims 1 to 3, characterized in that: It also includes a cooling medium storage module (202), which is connected to the circuit where the cooling medium flow channel is located and is used to adjust the degree of cold energy transfer of the cooling circulation circuit.

5. The refrigeration cycle VOCs low temperature condensation recovery system according to claim 1 is characterized in that: The mixed working medium refrigeration cycle circuit comprises a first mixed working medium refrigeration cycle circuit and a second mixed working medium refrigeration cycle circuit; The mixed working fluid heat regenerator comprises a first mixed working fluid heat regenerator (114) and a second mixed working fluid heat regenerator (123); The first mixed working medium refrigeration cycle loop further includes a first mixed working medium compressor (111), a first mixed working medium aftercooler (112), and a first mixed working medium throttling element (115); The first mixed working medium regenerator (114) is provided with a first mixed working medium flow channel a (1140), a first mixed working medium flow channel b (1141) and a first mixed working medium flow channel c (1142) inside; The first mixed working fluid compressor (111), the first mixed working fluid aftercooler (112), the first mixed working fluid flow channel a (1140), the first mixed working fluid throttling element (115), and the first mixed working fluid flow channel b (1141) are connected in sequence through pipelines, and the first mixed working fluid refrigeration cycle circuit is used to provide cold energy for cooling VOCs with relatively low cooling temperatures; The second mixed working medium refrigeration cycle further includes a second mixed working medium compressor (121), a second mixed working medium aftercooler (122), and a second mixed working medium throttling element (124); The second mixed working medium heat regenerator (123) is provided with a second mixed working medium flow channel a (1230), a second mixed working medium flow channel b (1231) and a second mixed working medium flow channel c (1232); The second mixed working fluid compressor (121), the second mixed working fluid aftercooler (122), the second mixed working fluid flow channel a (1230), the second mixed working fluid throttling element (124), and the second mixed working fluid flow channel b (1231) are connected in sequence through pipelines, and the second mixed working fluid refrigeration cycle circuit is used to provide cold energy for cooling VOCs with relatively high cooling temperature; The VOCs condensation pipeline is a total VOCs condensation pipeline, and the total VOCs condensation pipeline further comprises a first separator (314), a second separator (312), and an exhaust fan (303); the VOCs cooling heat exchanger (301) comprises a first VOCs cooling heat exchanger (313) and a second VOCs cooling heat exchanger (311); The first VOCs cooling heat exchanger (313) is provided with a first cooling channel a (3130), a first cooling channel b (3131) and a first cooling channel c (3132) inside; The second VOCs cooling heat exchanger (311) is provided with a second cooling channel a (3110), a second cooling channel b (3111) and a second cooling channel c (3112) inside; The second cooling channel b (3111), the exhaust channel of the second separator (312), the first cooling channel b (3131), the exhaust channel of the first separator (314), the first cooling channel c (3132), the second cooling channel c (3112), and the exhaust fan (303) are connected in sequence through pipelines; The first separator (314) is used to separate lighter hydrocarbons, and the second separator (312) is used to separate heavier hydrocarbons; The outlet of the cooling medium circulation driver (201) is respectively connected to the inlet of the first mixed medium flow channel c (1142) and the inlet of the second mixed medium flow channel c (1232) through the cooling medium flow channel; the outlet of the first mixed medium flow channel c (1142) is connected to the inlet of the first cooling flow channel a (3130) through the cooling medium flow channel; the outlet of the second mixed medium flow channel c (1232) and the outlet of the first cooling flow channel a (3130) are both connected to the inlet of the second cooling flow channel a (3110) through the cooling medium flow channel; the outlet of the second cooling flow channel a (3110) is connected to the inlet of the cooling medium circulation driver (201); The first separator (314) is a first distillation tower or a first condensation separator, wherein a first condensation component (215) is provided inside the first distillation tower or the first condensation separator, and a channel for circulating a cold medium in the first condensation component (215) is connected to the loop of the cold medium flow channel; The second separator (312) is a second distillation tower or a second condensation separator, and a second condensation component (213) is provided inside the second distillation tower or the second condensation separator. The channel for circulating the cold medium in the second condensation component (213) is connected to the loop of the cold medium flow channel.

6. The cold cycle VOCs low temperature condensation recovery system according to claim 5 is characterized in that: The first condensing component (215) is connected between the first mixed medium flow channel c (1142) and the first cooling flow channel a (3130); The second condensing component (213) is connected between the second mixed working fluid flow channel c (1232) and the second cooling flow channel a (3110).

7. The cold-carrying cycle VOCs low-temperature condensation recovery system according to claim 6 is characterized in that: It also includes a first cooling medium storage module (214) and a second cooling medium storage module (212); The first cooling medium storage module (214) is connected to the cooling medium flow channel between the first mixed medium flow channel c (1142) and the first condensing component (215); the second cooling medium storage module (212) is connected to the cooling medium flow channel between the second mixed medium flow channel c (1232) and the second condensing component (213); The first cooling medium storage module (214) and the second cooling medium storage module (212) are both used to adjust the degree of cold energy transfer of the cooling circulation loop.

8. The refrigeration cycle VOCs low temperature condensation recovery system according to any one of claims 5 to 7, characterized in that: Also includes a pre-cooling heat exchanger (113); The precooling heat exchanger (113) is provided with a precooling channel a (1130), a precooling channel b (1131), a precooling channel c (1132) and a precooling channel d (1133) inside; The inlet of the precooling channel a (1130) is connected to the outlet of the first mixed working medium aftercooler (112), and the outlet of the precooling channel a (1130) is connected to the inlet of the first mixed working medium channel a (1140); The inlet of the precooling flow channel b (1131) is connected to the outlet of the first mixed working medium flow channel b (1141), and the outlet of the precooling flow channel b (1131) is connected to the inlet of the first mixed working medium compressor (111); The inlet of the precooling channel c (1132) is connected to the outlet of the second mixed working medium aftercooler (122), and the outlet of the precooling channel c (1132) is connected to the inlet of the second mixed working medium channel a (1230); The inlet of the precooling channel d (1133) is connected to the outlet of the second mixed working medium channel b (1231), and the outlet of the precooling channel d (1133) is connected to the inlet of the second mixed working medium compressor (121).

9. The refrigeration cycle VOCs low temperature condensation recovery system according to claim 1, characterized in that: The cooling medium circulation driver (201) is a circulation pump; or, The cooling medium circulation driver (201) comprises a cooling medium compressor (221) and a cooling medium aftercooler (222).

10. The cold cycle VOCs low temperature condensation recovery system according to claim 1, characterized in that: The cooling medium in the cooling circulation loop is any one of propane, propylene, cyclopropane, isobutane, n-butane, 1-butene, isobutylene, isopentane, n-pentane, cyclopentane, n-hexane, ethane, ethylene, methane, nitrogen, argon, helium, neon, ammonia, air, R14, R23, R41, R116, R32, R125, R143a, R143, R22, R134a, R152a, R161, R218, R1234yf, R1234ze(E), fluorinated liquid, methanol, ethanol, and ethylene glycol, or a mixture of several of them.

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