VOCs low-temperature condensation recovery system with cold carrier circulation

Abstract

The present disclosure relates to the technical field of VOCs condensation recovery, and particularly relates to a cooling medium cycle VOCs low-temperature condensation recovery system, which comprises a mixed working medium refrigeration cycle loop and a VOCs condensation pipeline; the mixed working medium refrigeration cycle loop and the VOCs condensation pipeline transfer cold energy through a cooling medium cycle loop, the cooling medium cycle loop comprises a cooling medium cycle driver (201) and a cooling medium flow channel; the cooling medium flow channel is connected with a mixed working medium regenerator (103) in the mixed working medium refrigeration cycle loop, a VOCs cooling heat exchanger (301) in the VOCs condensation pipeline and the cooling medium cycle driver (201) in sequence; the cooling medium cycle loop makes the adjustment of cold energy more gentle and the adjustment range more extensive in the whole process, and can better condense the VOCs to be recovered with large flow and unstable working condition; in addition, the VOCs cooling heat exchanger arranged in the independent loop can be set according to the actual VOCs amount to be recovered, which reduces the complexity of design and makes the system smaller.

Description

Technical Field

[0001] This disclosure relates to the field of VOCs condensation and recovery technology, and in particular to a low-temperature condensation and recovery system for VOCs using a cooling cycle. Background Technology

[0002] VOCs, or volatile organic compounds, are harmful to the environment and human health. They mainly originate from processes such as coal chemical industry, petrochemical industry, fuel and coating manufacturing, and solvent manufacturing and use. The recovery of VOCs can prevent their pollution to the environment and also has certain economic value.

[0003] Currently, condensation is commonly used to recover VOCs, with two-stage and three-stage cascade refrigeration or liquid nitrogen refrigeration being the most frequently used methods. However, for cascade refrigeration, the multi-stage setup makes the entire condensation recovery equipment complex and costly. Liquid nitrogen refrigeration produces high-quality cold energy, but for VOCs with relatively high recovery temperatures, the supply and demand are mismatched, resulting in significant waste. In addition, indirect regenerative refrigeration technology, represented by mixed working fluid refrigeration, can distribute the gas load for cooling in its regenerative heat exchanger, reducing irreversible losses caused by large heat exchange temperature differences, which has certain positive significance. However, in actual processing, VOCs have low pressure, high flow rate, and drastic and unstable operating conditions. When VOCs directly exchange heat with the mixed working fluid, the heat exchanger requires numerous heat exchange channels to meet the demand, resulting in a complex and large-sized heat exchange equipment. At the same time, the sensitivity, timeliness, and range of adjustment cannot be effectively guaranteed. Summary of the Invention

[0004] To solve or partially solve the above-mentioned technical problems, this disclosure provides a low-temperature condensation and recovery system for VOCs in a cooling cycle.

[0005] This disclosure provides a low-temperature condensation and recovery system for VOCs in a cooling cycle, including a mixed working fluid refrigeration cycle loop and a VOCs condensation pipeline;

[0006] The mixed working fluid refrigeration cycle loop and the VOCs condensation pipeline transfer cold energy through the cooling cycle loop, which includes a cooling working fluid circulation driver and a cooling working fluid flow channel.

[0007] The cooling working fluid flow channel is sequentially connected to the mixed working fluid regenerator in the mixed working fluid refrigeration cycle loop, the VOCs cooling heat exchanger in the VOCs condensation pipeline, and the cooling working fluid circulation driver.

[0008] Optionally, the mixed refrigerant refrigeration cycle circuit further includes a mixed refrigerant compressor, a mixed refrigerant aftercooler, and a mixed refrigerant throttling element;

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

[0010] The mixed working medium compressor, the mixed working medium after-cooler, the mixed working medium flow channel a, the mixed working medium throttling element and the mixed working medium flow channel b are sequentially connected through pipelines;

[0011] The VOCs condensing pipeline further comprises a separator and an air extractor;

[0012] The VOCs cooling heat exchanger is internally provided with a cooling flow channel a, a cooling flow channel b and a cooling flow channel c;

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

[0014] The cooling medium flow channel sequentially connects the mixed working medium flow channel c, the cooling flow channel a and the cooling medium circulation driver.

[0015] Optionally, the separator is a rectifying tower or a condensation separator, and the rectifying tower or the condensation separator is internally provided with a condensation assembly, and a passage through which a cooling medium flows is connected in the cooling circulation loop.

[0016] Optionally, the cooling medium storage module is connected in the loop in which the cooling medium flow channel is located, and is used for adjusting the cold energy transmission degree of the cooling circulation loop.

[0017] Optionally, the mixed working medium refrigeration circulation loop comprises a first mixed working medium refrigeration circulation loop and a second mixed working medium refrigeration circulation loop;

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

[0019] The first mixed working medium refrigeration circulation loop further comprises a first mixed working medium compressor, a first mixed working medium after-cooler and a first mixed working medium throttling element;

[0020] The first mixed working medium regenerator is internally 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;

[0021] The first mixed working medium compressor, the first mixed working medium after-cooler, the first mixed working medium flow channel a, the first mixed working medium throttling element, the first mixed working medium flow channel b are sequentially connected through pipelines, and the first mixed working medium refrigeration circulation loop is used for providing cold energy for VOCs with a relatively low cooling temperature;

[0022] The second mixed working medium refrigeration cycle circuit further comprises a second mixed working medium compressor, a second mixed working medium after-cooler, 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 medium compressor, the second mixed working medium after-cooler, the second mixed working medium flow channel a, the second mixed working medium throttling element, the second mixed working medium flow channel b are sequentially connected through pipelines, and the second mixed working medium refrigeration cycle circuit is used for providing cold energy for VOCs with a relatively high cooling temperature;

[0025] The VOCs condensing pipeline is a total VOCs condensing pipeline, and the total VOCs condensing pipeline further comprises a first separator, a second separator and a gas extractor; the VOCs cooling heat exchanger comprises a first VOCs cooling heat exchanger and a second VOCs cooling heat exchanger;

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

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

[0028] The second cooling flow channel b, an exhaust passage of the second separator, the first cooling flow channel b, an exhaust passage of the first separator, the first cooling flow channel c, the second cooling flow channel c and the gas extractor are sequentially connected through pipelines;

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

[0030] An outlet of the cold-carrying working medium circulation driver is connected to an inlet of the first mixed working medium flow channel c and an inlet of the second mixed working medium flow channel c through the cold-carrying working medium flow channel, an outlet of the first mixed working medium flow channel c is connected to an inlet of the first cooling flow channel a through the cold-carrying working medium flow channel, and an outlet of the second mixed working medium flow channel c and an outlet of the first cooling flow channel a are both connected to an inlet of the second cooling flow channel a through the cold-carrying working medium flow channel, and an outlet of the second cooling flow channel a is connected to an inlet of the cold-carrying working medium circulation driver;

[0031] The first separator is a first rectifying tower or a first condensation separator, and the first rectifying tower or the first condensation separator is internally provided with a first condensing assembly, and a passage through which a cold medium flows in the first condensing assembly is connected in a loop of the cold-carrying working medium flow channel;

[0032] The second separator is a second rectifying column or a second condensation separator, and a second condensing assembly is arranged inside the second rectifying column or the second condensation separator, and a channel through which a cold medium flows is connected in a loop of the cold medium flow channel.

[0033] Optionally, the first condensing assembly is connected between the first mixed working medium flow channel c and the first cooling flow channel a.

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

[0035] Optionally, the first cold storage medium storage module and the second cold storage medium storage module are further included.

[0036] The first cold storage medium storage module is connected to the cold medium flow channel between the first mixed working medium flow channel c and the first condensing assembly, and the second cold storage medium storage module is connected to the cold medium flow channel between the second mixed working medium flow channel c and the second condensing assembly.

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

[0038] Optionally, a pre-cooling heat exchanger is further included.

[0039] The pre-cooling heat exchanger is internally provided with a pre-cooling flow channel a, a pre-cooling flow channel b, a pre-cooling flow channel c and a pre-cooling flow channel d.

[0040] The inlet of the pre-cooling flow channel a is connected with the outlet of the first mixed working medium after-cooler, and the outlet of the pre-cooling flow channel a is connected with the inlet of the first mixed working medium flow channel a.

[0041] The inlet of the pre-cooling flow channel b is connected with the outlet of the first mixed working medium flow channel b, and the outlet of the pre-cooling flow channel b is connected with the inlet of the first mixed working medium compressor.

[0042] The inlet of the pre-cooling flow channel c is connected with the outlet of the second mixed working medium after-cooler, and the outlet of the pre-cooling flow channel c is connected with the inlet of the second mixed working medium flow channel a.

[0043] The inlet of the pre-cooling flow channel d is connected with the outlet of the second mixed working medium flow channel b, and the outlet of the pre-cooling flow channel d is connected with the inlet of the second mixed working medium compressor.

[0044] Optionally, the cold storage medium circulation driver is a circulation pump.

[0045] Or,

[0046] The cold-carrying medium circulation driver is a cold-carrying medium compressor and a cold-carrying medium after-cooler.

[0047] Optionally, the cold-carrying medium in the cold-carrying circulation loop is any 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 thereof.

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

[0049] The cold-carrying circulation VOCs low-temperature condensation recovery system provided by the present disclosure is under the action of the cold-carrying circulation loop, the loop in which the mixed working medium regenerator is located and the loop directly participating in VOCs recovery are independent of each other while maintaining the transfer of cold energy. Meanwhile, the setting of the cold-carrying circulation loop makes the adjustment of cold energy in the whole process more gentle and the adjustment range more extensive. For the VOCs to be recovered with large flow and unstable working conditions, the condensation can be better. In addition, the VOCs cooling heat exchanger set in the independent loop can be set according to the actual VOCs amount to be recovered, greatly reducing the complexity of design, and the system is smaller in size and less limited by the environment. Moreover, due to the existence of the intermediate cold-carrying loop for adjustment, the loop in which the VOCs cooling heat exchanger set in the independent loop can more flexibly cope with the actual VOCs amount to be recovered to make the pipeline flexible and optional, without worrying about whether the changes directly affect the efficiency of heat exchange, thereby improving the adaptability to the specific conditions of the VOCs to be recovered. BRIEF DESCRIPTION OF DRAWINGS

[0050] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present disclosure and, together with the specification, serve to explain the principles of the present disclosure.

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, other drawings can also be obtained by those skilled in the art without creative labor.

[0052] Figure 1 Structure diagram of the cold-carrying circulation VOCs low-temperature condensation recovery system described in the present disclosure;

[0053] Figure 2 An embodiment structure schematic diagram of a cold storage circulating VOCs low-temperature condensation recovery system according to the present disclosure is provided with a cold storage medium storage module;

[0054] Figure 3 An embodiment structure schematic diagram of a cold storage circulating VOCs low-temperature condensation recovery system according to the present disclosure is provided with a separator being a rectifying column;

[0055] Figure 4 An embodiment structure schematic diagram of a cold storage circulating VOCs low-temperature condensation recovery system according to the present disclosure is provided with a separator being a condensation separator;

[0056] Figure 5 An embodiment structure schematic diagram of a cold storage circulating VOCs low-temperature condensation recovery system according to the present disclosure is provided with a cold storage medium circulating driver being a cold storage medium compressor and a cold storage medium after-cooler;

[0057] Figure 6 An embodiment structure schematic diagram of a cold storage circulating VOCs low-temperature condensation recovery system according to the present disclosure is provided for different VOCs condensation temperatures.

[0058] Wherein, 101, mixed working medium compressor; 102, mixed working medium after-cooler; 103, mixed working medium regenerator; 1030, mixed working medium flow channel a; 1031, mixed working medium flow channel b; 1032, mixed working medium flow channel c; 104, mixed working medium throttling element; 111, first mixed working medium compressor; 112, first mixed working medium after-cooler; 113, pre-cooling heat exchanger; 1130, pre-cooling flow channel a; 1131, pre-cooling flow channel b; 1132, pre-cooling flow channel c; 1133, pre-cooling 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 after-cooler; 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; 124, second mixed working medium throttling element; 201, cooling medium circulation driver; 202, cooling medium storage module; 203, condensing assembly; 212, second cooling medium out-storage module; 213, second condensing assembly; 214, first cooling medium storage module; 215, first condensing assembly; 216, pipe distributor; 217, pipe mixer; 221, cooling medium compressor; 222, cooling medium after-cooler; 301, VOCs cooling heat exchanger; 3010, cooling flow channel a; 3011, cooling flow channel b; 3012, cooling flow channel c; 302, separator; 303, air extractor; 311, second VOCs cooling heat exchanger; 3110, second cooling flow channel a; 3111, second cooling flow channel b; 3112, second cooling flow channel c; 312, second separator; 313, first VOCs cooling heat exchanger; 3130, first cooling flow channel a; 3131, first cooling flow channel b; 3132, first cooling flow channel c; 314, first separator. DETAILED DESCRIPTION

[0059] In order to enable a more clear understanding of the above-mentioned objects, features and advantages of the present disclosure, the schemes 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, a large number of specific details are set forth in order to facilitate a thorough understanding of the present disclosure, but the present disclosure can also be implemented in other manners different from those described herein; obviously, the embodiments described in the specification are only a part of the embodiments of the present disclosure, and not all the embodiments.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," or "having" and variations thereof herein is intended to be broad and encompass the terms "consisting of" and "consisting essentially of" and variations thereof. Unless otherwise required by context, singular terms shall include pluralities and vice versa.

[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 explicitly and specifically limited.

[0063] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can 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, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0065] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and 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", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0067] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "linking", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled 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] Referring to Figure 1 As shown in the figure, the cold-carrying cycle VOCs low-temperature condensation recovery system provided by the embodiment includes a mixed working medium refrigeration cycle loop and a VOCs condensation pipeline; the mixed working medium refrigeration cycle loop and the VOCs condensation pipeline transfer cold energy through a cold-carrying cycle loop, and the cold-carrying cycle loop includes a cold-carrying working medium cycle driver 201 and a cold-carrying working medium flow channel; under the action of the cold-carrying cycle loop, the mixed working medium refrigeration cycle loop and the VOCs condensation pipeline are independent of each other and simultaneously maintain the transfer of cold energy. At the same time, the setting of the cold-carrying cycle makes the adjustment of cold energy in the whole process more gentle, and the adjustment range is more extensive. For the VOCs to be recovered with large flow and unstable working conditions, the VOCs can be better condensed. In addition, the mixed working medium refrigeration cycle loop set independently can be set according to the actual VOCs to be recovered, greatly reducing the complexity of design, occupying less space, and being less limited by the environment. Moreover, due to the existence of the cold-carrying cycle for adjustment, the VOCs condensation pipeline set independently can more flexibly cope with the actual VOCs to be recovered to make the pipeline flexible and optional, without worrying about whether the changes directly affect the heat exchange efficiency, and improving the adaptability to the VOCs to be recovered.

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

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

[0071] Specifically, the working fluid compressor 101, working fluid aftercooler 102, working fluid flow channel a1030, working fluid throttling element 104, and working fluid flow channel b1031 are connected sequentially by pipes. In actual operation, the working fluid is compressed in the working fluid compressor 101, and its temperature rises after compression. Then, it passes through the working fluid aftercooler 102, where it is cooled to a certain extent. After cooling, it enters the working fluid flow channel a1030 to participate in heat exchange and cooling. After passing through the working fluid throttling element 104 for further cooling and depressurization, it re-enters the working fluid compressor 101 through the working fluid flow channel b1031 for circulation.

[0072] It should be noted that heat exchange can occur 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, which will simultaneously reduce the temperature of the mixed working fluid flowing in the mixed working fluid flow channel a1030, thereby achieving positive feedback in refrigeration and ensuring refrigeration efficiency.

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

[0074] The cooling working fluid flow channel in the cooling circulation loop is sequentially connected to the mixing working fluid flow channel c1032, the cooling flow channel a3010, and the cooling working fluid circulation driver 201. The cooling working fluid in the cooling circulation loop exchanges heat with the mixed working fluid in the mixing working fluid flow channel b1031 in the mixing working fluid flow channel c1032, thereby achieving cooling of the cooling working fluid 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, thereby achieving cooling of the VOCs. The cooling circulation loop is equivalent to adding an extra regulating loop, increasing the regulation range, and also increasing the smoothness of regulation.

[0075] refer to Figure 3and Figure 4 As shown in some further embodiments, the separator 302 is a rectifying tower or a fractionating separator, and the condensing assembly 203 is arranged inside the rectifying tower or the fractionating separator, and the channel for circulating the cold mass in the condensing assembly 203 is connected in the cooling cycle loop; in addition to directly participating in heat exchange in the VOCs condensing pipeline, the cold mass in the cooling medium flow channel will also pass through the channel for circulating the cold mass in the condensing assembly 203, so as to increase the condensing effect and better promote the separation of the gas and the hydrocarbon in the VOCs.

[0076] In addition, the condensing assembly 203 can adopt a variety of forms such as a tube form, a coil form, a finned tube form, and a micro-channel form.

[0077] Further, in some embodiments, when the separator 302 is a rectifying tower, the condensing assembly 203 can be arranged at the top of the rectifying tower or at the middle of the rectifying tower, and of course, in some other cases such as a large flow, a plurality of condensing assemblies 203 can be arranged at the top and the middle of the rectifying tower at the same time, so as to better ensure the efficiency of the gas-liquid separation and reduce the residue of the hydrocarbon in the VOCs to be recovered.

[0078] Reference Figure 2 As shown in some further embodiments, the cooling medium storage module 202 is connected in the loop where the cooling medium flow channel is located, and is used to adjust the degree of cold energy transmission of the cooling cycle loop; in the process of VOCs condensing recovery, the recovery temperatures of different hydrocarbons are different, and in order to more accurately adjust the temperature, the cooling medium storage module 202 is arranged in the cooling cycle loop, and 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 low, a part of the cooling medium in the cooling cycle loop can be released to the storage container by adjusting the control valve group, so as to appropriately reduce the degree of cold energy transmission of the cooling cycle loop, so as to accurately meet the requirements and avoid waste; and when the required VOCs cooling temperature needs to be low, the cooling medium in the storage container can be released by adjusting the control valve group, so as to increase the degree of cold energy transmission of the cooling cycle loop, so as to meet the requirements and ensure normal cooling.

[0079] It can be conceived that in some further embodiments, a pipeline for injecting the cooling medium can be arranged on the storage container, and the cooling medium can be injected into the cooling cycle loop when the required cooling temperature is low, so as to ensure normal cooling.

[0080] Reference Figure 6 As shown, the mixed refrigerant cycle loop includes a first mixed refrigerant cycle loop and a second mixed refrigerant cycle loop.

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

[0082] The first mixed working medium refrigeration cycle circuit further includes a first mixed working medium compressor 111, a first mixed working medium after-cooler 112, a first mixed working medium throttling element 115, and the first mixed working medium regenerator 114, which is internally 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.

[0083] The first mixed working medium compressor 111, the first mixed working medium after-cooler 112, the first mixed working medium flow channel a 1140, the first mixed working medium throttling element 115, and the first mixed working medium flow channel b 1141 are sequentially connected through pipelines, and the first mixed working medium refrigeration cycle circuit is used to provide cold energy for VOCs with a relatively low cooling temperature; and the first mixed working medium refrigeration cycle circuit is mainly used to separate relatively light hydrocarbons.

[0084] The second mixed working medium refrigeration cycle circuit further includes a second mixed working medium compressor 121, a second mixed working medium after-cooler 122, a second mixed working medium throttling element 124, and the second mixed working medium regenerator 123, which 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.

[0085] The second mixed working medium compressor 121, the second mixed working medium after-cooler 122, the second mixed working medium flow channel a 1230, the second mixed working medium throttling element 124, and the second mixed working medium flow channel b 1231 are sequentially connected through pipelines, and the second mixed working medium refrigeration cycle circuit is used to provide cold energy for VOCs with a relatively high cooling temperature; and the second mixed working medium refrigeration cycle circuit is mainly used to separate relatively middle hydrocarbons.

[0086] The VOCs condensing pipeline is a total VOCs condensing pipeline, and the total VOCs condensing pipeline includes a first separator 314, a second separator 312, and an air extractor 303; and 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 internally provided with a first cooling flow channel a 3130, a first cooling flow channel b 3131, and a first cooling flow channel c 3132; and the second VOCs cooling heat exchanger 311 is internally provided with a second cooling flow channel a 3110, a second cooling flow channel b 3111, and a second cooling flow channel c 3112.

[0088] The second cooling flow channel b3111, the exhaust passage of the second separator 312, the first cooling flow channel b3131, the exhaust passage of the first separator 314, the first cooling flow channel c3132, the second cooling flow channel c3112, and the air extractor 303 are sequentially connected through pipes; the first separator 314 is used for separating relatively light hydrocarbons, and the second separator 312 is used for separating relatively heavy hydrocarbons, corresponding to the first mixed working medium refrigeration cycle and the second mixed working medium refrigeration cycle respectively.

[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 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; and the outlet of the second cooling flow channel a3110 is connected to the inlet of the cooling medium circulation driver 201.

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

[0091] The original cold energy supply circuit is improved into a supply circuit under two different temperature steps by setting the first mixed working medium refrigeration cycle loop and the second mixed working medium refrigeration cycle loop, so that the supply of cold energy can be performed correspondingly when facing relatively heavy hydrocarbons and relatively light hydrocarbons in the VOCs; for example, when the relatively light hydrocarbons are separated, the cooling temperature required is low, at this time, the refrigeration of the first mixed working medium refrigeration cycle loop can be increased alone, so as to meet the lower temperature requirement; when the relatively heavy hydrocarbons are separated, the cooling temperature required is high, at this time, the refrigeration of the second mixed working medium refrigeration cycle loop can be reduced alone, so as to meet the higher temperature requirement; in this mode, the supply and demand are appropriate, and the waste of cold energy is avoided, and the demand of different VOCs for cold energy is met, so that the condensation and recovery of the VOCs are finally 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 working medium flow channel c1142 and the second mixed working medium flow channel c1232 through the pipe distributor 216 respectively.

[0093] In some other embodiments, the cooling medium flowing out of the first cooling flow channel a3130 and the cooling medium flowing out of the second mixed working medium flow channel c1232 can be mixed by the pipe mixer 217 and then enter the second cooling flow channel a3110 to realize the sequence.

[0094] It should be noted that the cooling medium passing through the first cooling flow channel a3130 will have a higher temperature after heat exchange with the first cooling flow channel b3131. At this time, the cooling medium will participate in the heat exchange circuit for condensing and recovering VOCs with a higher required temperature, i.e., the second cooling flow channel a3110, through the pipe mixer 217, thereby realizing heat exchange and cooling of VOCs with different temperature requirements in sequence, fully utilizing the cold energy provided by the cooling medium, and avoiding waste under the premise of ensuring supply and demand.

[0095] In some other embodiments, the first separator 314 is a first rectifying tower or a first condensation separator, and the first rectifying tower or the first condensation separator is internally provided with the first condensing assembly 215, and the channel for flowing through the cooling medium in the first condensing assembly 215 is connected in the cooling circulating loop; the second separator 312 is a second rectifying tower or a second condensation separator, and the second rectifying tower or the second condensation separator is internally provided with the second condensing assembly 213, and the channel for flowing through the cooling medium in the second condensing assembly 213 is connected in the cooling medium flow channel loop. After the cooling medium flows through the first condensing assembly 215 and the second condensing assembly 213, the gas-liquid separation in the first separator 314 and the second separator 312 can be more thorough, so as to reduce the hydrocarbons in the gas to the greatest extent and ensure the recovery effect.

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

[0097] In some further embodiments, the first cold carrier storage module 214 and the second cold carrier storage module 212 are further included: the first cold carrier storage module 214 is connected to the cold carrier flow channel between the first mixed working medium flow channel c1142 and the first condensing assembly 215; the second cold carrier storage module 212 is connected to the cold carrier flow channel between the second mixed working medium flow channel c1232 and the second condensing assembly 213; the first cold carrier storage module 214 and the second cold carrier storage module 212 are both used to adjust the cold energy transmission degree of the cold carrier circulation loop; the first cold carrier storage module 214 and the second cold carrier storage module 212 can both be storage containers and corresponding control valves to adjust the cold energy transmission degree of the loop when responding to different temperature requirements; at the same time, it is necessary to point out that when more than two cold carrier storage modules 202 are arranged in the entire cold carrier circulation loop, the control of the cold energy transmission degree of the cold carrier circulation loop can be more accurate.

[0098] In some further embodiments, the pre-cooling heat exchanger 113 is further included; the pre-cooling heat exchanger 113 is internally provided with a pre-cooling flow channel a1130, a pre-cooling flow channel b1131, a pre-cooling flow channel c1132 and a pre-cooling flow channel d1133; the inlet of the pre-cooling flow channel a1130 is connected with the outlet of the first mixed working medium after-cooler 112, and the outlet of the pre-cooling flow channel a1130 is connected with the inlet of the first mixed working medium flow channel a1140; the inlet of the pre-cooling flow channel b1131 is connected with the outlet of the first mixed working medium flow channel b1141, and the outlet of the pre-cooling flow channel b1131 is connected with the inlet of the first mixed working medium compressor 111; the inlet of the pre-cooling flow channel c1132 is connected with the outlet of the second mixed working medium after-cooler 122, and the outlet of the pre-cooling flow channel c1132 is connected with the inlet of the second mixed working medium flow channel a1230; the inlet of the pre-cooling flow channel d1133 is connected with the outlet of the second mixed working medium flow channel b1231, and the outlet of the pre-cooling flow channel d1133 is connected with the inlet of the second mixed working medium compressor 121.

[0099] The pre-cooling heat exchanger 113 is used to reduce the large temperature heat exchange difference and avoid the irreversible loss of cold energy; specifically, the first mixed working medium in the first mixed working medium refrigeration cycle passes through the first mixed working medium compressor 111 and the first mixed working medium after-cooler 112, enters the pre-cooling flow channel a1130 and is cooled to a pre-cooling temperature (generally -20℃-10℃), and then passes through the first mixed working medium flow channel a1140, is cooled and decompressed by the first mixed working medium throttling element 115, and then sequentially flows through the first mixed working medium flow channel b1141, the pre-cooling flow channel b1131 and the first mixed working medium compressor 111 to realize the circulation. It is necessary to point out that the pre-cooling flow channel a1130 and the pre-cooling flow channel b1131, and the first mixed working medium flow channel a1140 and the first mixed working medium flow channel b1141 all realize the positive feedback cooling heat exchange to ensure the cooling effect.

[0100] The flow process of the second mixed working medium is the same as that of the first mixed working medium, which will not be described here.

[0101] Reference Figure 5 As shown in some further embodiments, the cold carrier medium circulation driver 201 is a circulation pump; or, the cold carrier medium circulation driver 201 is a cold carrier medium compressor 221 and a cold carrier medium after-cooler 222, the temperature of the working medium after compression will be increased to a certain extent, so the cold carrier medium compressor 221 and the cold carrier medium after-cooler 222 are arranged in combination to serve as the cold carrier medium circulation driver 201.

[0102] It should be noted that the above-mentioned mixed working medium, the first mixed working medium, and the second mixed working medium 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, R1234ze(E); and the cold carrier medium 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 thereof.

[0103] The specific implementation and implementation principles are the same as those of the above-mentioned embodiments and can bring the same or similar technical effects, which will not be described here one by one, and the specific description can be referred to the description of the above-mentioned cold carrier circulation VOCs low-temperature condensation recovery system embodiments.

[0104] The above is only a specific implementation of the present disclosure, enabling those skilled in the art to 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 can 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 these embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cold circulating VOCs cryogenic condensation recovery system, characterized in that, The mixed working medium refrigeration cycle loop and the VOCs condensing pipeline are connected through a cooling circulating loop, and the cooling circulating loop comprises a cooling working medium circulation driver (201) and a cooling working medium flow channel. The cooling working medium flow channel is sequentially connected with a mixed working medium regenerator (103) in the mixed working medium refrigeration cycle loop, a VOCs cooling heat exchanger (301) in the VOCs condensing pipeline, and the cooling working medium circulation driver (201). The mixed working medium refrigeration cycle loop comprises a first mixed working medium refrigeration cycle loop and a second mixed working medium refrigeration cycle loop. The mixed working medium regenerator comprises a first mixed working medium regenerator (114) and a second mixed working medium regenerator (123). The first mixed working medium refrigeration cycle loop further comprises a first mixed working medium compressor (111), a first mixed working medium after-cooler (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 a (1140), a first mixed working medium flow channel b (1141), and a first mixed working medium flow channel c (1142). The first mixed working medium compressor (111), the first mixed working medium after-cooler (112), the first mixed working medium flow channel a (1140), the first mixed working medium throttling element (115), and the first mixed working medium flow channel b (1141) are sequentially connected through pipelines, and the first mixed working medium refrigeration cycle loop is used for providing cold energy for VOCs with a relatively low cooling temperature. The second mixed working medium refrigeration cycle loop further comprises a second mixed working medium compressor (121), a second mixed working medium after-cooler (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 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 medium compressor (121), the second mixed working medium after-cooler (122), the second mixed working medium flow channel a (1230), the second mixed working medium throttling element (124), and the second mixed working medium flow channel b (1231) are sequentially connected through pipelines, and the second mixed working medium refrigeration cycle loop is used for providing cold energy for VOCs with a relatively high cooling temperature. The VOCs condensing pipeline is a total VOCs condensing pipeline, and the total VOCs condensing pipeline further comprises a first separator (314), a second separator (312), and an air extractor (303). The first VOCs cooling heat exchanger (313) is internally provided with a first cooling flow channel a (3130), a first cooling flow channel b (3131), and a first cooling flow channel c (3132). ​ The second VOCs cooling heat exchanger (311) is internally provided with a second cooling flow channel a (3110), a second cooling flow channel b (3111) and a second cooling flow channel c (3112); The second cooling flow channel b (3111), the exhaust passage of the second separator (312), the first cooling flow channel b (3131), the exhaust passage of the first separator (314), the first cooling flow channel c (3132), the second cooling flow channel c (3112) and the air extractor (303) are sequentially connected through pipelines; The first separator (314) is used for separating lighter hydrocarbons, and the second separator (312) is used for separating heavier hydrocarbons; The outlet of the cold carrier working medium circulation driver (201) is connected to the inlet of the first mixed working medium flow channel c (1142) and the inlet of the second mixed working medium flow channel c (1232) through the cold carrier working medium flow channel, the outlet of the first mixed working medium flow channel c (1142) is connected to the inlet of the first cooling flow channel a (3130) through the cold carrier working medium flow channel, and the outlet of the second mixed working 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 cold carrier working medium flow channel, and the outlet of the second cooling flow channel a (3110) is connected to the inlet of the cold carrier working medium circulation driver (201); The first separator (314) is a first rectifying tower or a first condensation separator, and a first condensing assembly (215) is arranged in the first rectifying tower or the first condensation separator, and a channel through which a cold medium flows in the first condensing assembly (215) is connected in a loop of the cold carrier working medium flow channel; The second separator (312) is a second rectifying tower or a second condensation separator, and a second condensing assembly (213) is arranged in the second rectifying tower or the second condensation separator, and a channel through which a cold medium flows in the second condensing assembly (213) is connected in the loop of the cold carrier working medium flow channel.

2. The subcooling cycle VOCs subcooling recovery system of claim 1, wherein, The first condensing assembly (215) is connected between the first mixed working medium flow channel c (1142) and the first cooling flow channel a (3130); The second condensing assembly (213) is connected between the second mixed working medium flow channel c (1232) and the second cooling flow channel a (3110).

3. The subcooling cycle VOCs cryocondensation recovery system of claim 2, wherein, Further comprising a first cold carrier working medium storage module (214) and a second cold carrier working medium storage module (212); The first cold carrier working medium storage module (214) is connected to the cold carrier working medium flow channel between the first mixed working medium flow channel c (1142) and the first condensing assembly (215), and the second cold carrier working medium storage module (212) is connected to the cold carrier working medium flow channel between the second mixed working medium flow channel c (1232) and the second condensing assembly (213); The first cold carrier working medium storage module (214) and the second cold carrier working medium storage module (212) are both used for adjusting the cold energy transmission degree of the cold carrier circulation loop.

4. The subcooling cycle VOCs subcooling recovery system according to any one of claims 1-3, wherein, Further comprising a precooling heat exchanger (113); The precooling heat exchanger (113) is internally provided with a precooling flow channel a (1130), a precooling flow channel b (1131), a precooling flow channel c (1132) and a precooling flow channel d (1133); The inlet of the precooling flow channel a (1130) is connected with the outlet of the first mixed working medium after-cooler (112), and the outlet of the precooling flow channel a (1130) is connected with the inlet of the first mixed working medium flow channel a (1140); The inlet of the precooling flow channel b (1131) is connected with the outlet of the first mixed working medium flow channel b (1141), and the outlet of the precooling flow channel b (1131) is connected with the inlet of the first mixed working medium compressor (111); The inlet of the precooling flow channel c (1132) is connected with the outlet of the second mixed working medium after-cooler (122), and the outlet of the precooling flow channel c (1132) is connected with the inlet of the second mixed working medium flow channel a (1230); The inlet of the precooling flow channel d (1133) is connected with the outlet of the second mixed working medium flow channel b (1231), and the outlet of the precooling flow channel d (1133) is connected with the inlet of the second mixed working medium compressor (121).

5. The subcooling cycle VOCs subcooling recovery system of claim 1, wherein, The cooling medium circulation driver (201) is a circulation pump; Or, The cooling medium circulation driver (201) is a cooling medium compressor (221) and a cooling medium after-cooler (222).

6. The subcritical VOCs cryogenic condensation recovery system of claim 1, wherein, The cooling medium in the cooling cycle loop is any 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 thereof.

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