Energy coupling closed-loop recycling and pressurizing system for carbon dioxide phase change fluid

Abstract

An energy coupling closed-loop recovery pressurization system for carbon dioxide phase change fluid is characterized in that an entanglement cavity is communicated with a recovery unit, the recovery unit is communicated with a condensation liquefaction module, a preheater and a high-pressure fluid generation module, and the high-pressure fluid generation module is communicated with the entanglement cavity. Gas is collected and compressed twice by the compression unit, compression heat is supplied to the preheater, the gas is liquefied into liquid by the condensation and liquefaction module, the liquid is heated by the preheater, then the liquid is pressurized by the high-pressure fluid generation module to obtain fluid, and the fluid enters the entanglement cavity and is sprayed as fluid jet flow; compression is divided into two times, compared with one-time compression, energy consumption is reduced, and heating energy consumption of the preheater is also reduced through recycling of compression heat. Therefore, when non-aqueous medium fluid is adopted for fiber web entanglement, the energy consumption of fluid phase state treatment is low, and a heat recycling function is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to a carbon dioxide phase change fluid recovery design, belonging to the field of non-woven fabric entanglement reinforcement and green manufacturing technology, in particular to an energy coupling closed loop recovery pressurization system of carbon dioxide phase change fluid. BACKGROUND

[0002] In the field of non-woven fabrics, water jet technology is a unique and new web consolidation technology, which uses multiple fine water jets to spray the web to complete the entanglement and reinforcement of the web. However, a large amount of water resources are needed in this process, and drying and water treatment are also needed, which consumes a lot of energy. Therefore, a non-aqueous medium is needed, which forms a fluid jet under pressure to replace water and entangle and reinforce the fiber web in the entanglement chamber, and the fluid is gasified after entanglement (for example, a non-aqueous reinforcement method for enhancing entanglement of fiber web by phase change fluid in Chinese patent application No. 2025116011678).

[0003] The fluid jet can be collected and re-liquefied after gasification to achieve recycling effect, but the phase state processing of gas and fluid involves a lot of compression work and heat, and a lot of compression heat generated during compression is directly discarded as waste heat, and external energy is needed to preheat the liquid carbon dioxide, resulting in low overall energy utilization efficiency and high operating cost, that is, there is a problem of high energy consumption.

[0004] The core idea of the present application is to build an energy coupling closed loop system to comprehensively utilize the energy generated in the whole process of entanglement, recovery, liquefaction, preheating and re-pressurization of carbon dioxide phase change fluid, especially the compression heat generated in the compression process of the recovery unit for preheating liquid carbon dioxide, thereby significantly reducing the demand for external energy and achieving energy saving and consumption reduction.

[0005] The information disclosed in this background section is intended only to increase an understanding of the general context of the present application, and should not be taken as an acknowledgement or any form of suggestion that this information forms prior art that is already widely known in the art. SUMMARY

[0006] The purpose of the present application is to overcome the defects and problems of high energy consumption of fluid phase state processing when using non-aqueous medium fluid for web entanglement in the prior art, and to provide an energy coupling closed loop recovery pressurization system of carbon dioxide phase change fluid with low energy consumption of fluid phase state processing when using non-aqueous medium fluid for web entanglement.

[0007] To achieve the above purpose, the technical solution of the present application is: ​

[0008] An energy coupling closed loop recovery pressurization system of carbon dioxide phase change fluid, the system comprising an entanglement chamber, a recovery unit, a condensation liquefaction module and a high pressure fluid generation module;

[0009] The middle part of the entanglement chamber is provided with a channel for the fiber web to pass through, and the top of the entanglement chamber is provided with a nozzle, which sprays fluid jet towards the direction of the fiber web, and the fluid jet entangles the fiber web;

[0010] The top of the entanglement chamber is in communication with the input end of the collection cover in the recovery unit;

[0011] The output end of the collection cover is in communication with the input end of the primary compression unit, and the primary compression unit supplies heat to the liquid carbon dioxide preheater;

[0012] The output end of the primary compression unit is in communication with the input end of the secondary compression unit, and the secondary compression unit supplies heat to the liquid carbon dioxide preheater;

[0013] The output end of the secondary compression unit is in communication with the input end of the condensation liquefaction module;

[0014] The output end of the condensation liquefaction module is in communication with the input end of the liquid carbon dioxide preheater;

[0015] The output end of the liquid carbon dioxide preheater is in communication with the input end of the high pressure fluid generation module;

[0016] The output end of the high pressure fluid generation module is in communication with the input end of a plurality of nozzles.

[0017] The condensation liquefaction module comprises a fine condenser and a liquid carbon dioxide storage tank, and the input end of the fine condenser is in communication with the output end of the secondary compression unit;

[0018] The output end of the fine condenser is in communication with the input end of the liquid carbon dioxide storage tank;

[0019] The output end of the liquid carbon dioxide storage tank is in communication with the input end of the liquid carbon dioxide preheater.

[0020] The collection cover comprises a high pressure section, a mixing section and a low pressure section;

[0021] The high pressure section comprises a high pressure large end and a high pressure small end in sequence, the diameter of the high pressure large end gradually decreases to the diameter of the high pressure small end, and one end of the high pressure small end is in communication with one end of the mixing section;

[0022] Another end of the mixing section is communicated with one end of a low pressure small end in the low pressure section, another end of the low pressure small end is communicated with one end of a low pressure large end, the diameter of the low pressure small end is gradually increased to the diameter of the low pressure large end, another end of the low pressure large end is communicated with the input end of the first compression unit;

[0023] The middle part of the mixing section is vertically communicated with one end of a suction pipeline, and another end of the suction pipeline is communicated with the top of the entangling cavity.

[0024] The suction pipeline has an ejection ratio of three to one to ten to one with the high pressure section.

[0025] The high pressure section, the mixing section and the low pressure section are made of stainless steel 316L material.

[0026] The high pressure fluid generating module comprises a micro-channel heat exchanger and a pressurizing unit, the micro-channel heat exchanger comprises a plurality of low pressure channels and a plurality of high pressure channels, adjacent high pressure channels and low pressure channels share a side wall, and the side wall is made of heat-conducting material.

[0027] The inlet end of the low pressure channel is communicated with the outlet end of the liquid carbon dioxide preheater, and the outlet end of the low pressure channel is communicated with the inlet end of the pressurizing unit; the outlet end of the pressurizing unit is communicated with the inlet end of the high pressure channel, and the outlet end of the high pressure channel is communicated with the input end of the plurality of nozzles.

[0028] The temperature in the high pressure channel is 35-60 DEG C, and the temperature in the low pressure channel is 25-50 DEG C.

[0029] The liquid carbon dioxide preheater is a plate heat exchanger.

[0030] The temperature of the outlet end of the liquid carbon dioxide preheater is 25-31 DEG C.

[0031] The system comprises an intelligent control system, the intelligent control system comprises sensors, an intelligent control unit and an actuator, a plurality of the sensors are respectively installed at the outlet end of the collection cover, the outlet end of the first compression unit, the outlet end of the second compression unit, the outlet end of the liquid carbon dioxide preheater and the outlet end of the high pressure fluid generating module, the sensors are signal connected with the intelligent control unit, and the intelligent control unit is signal connected with the actuator.

[0032] Compared with the prior art, the beneficial effects of the present application are:

[0033] 1. In the energy coupling closed loop recycling pressurization system of the carbon dioxide phase change fluid, the system comprises an entanglement cavity, a recycling unit, a condensation liquefaction module and a high-pressure fluid generation module, a channel for the fiber web to pass through is arranged in the middle of the entanglement cavity, nozzles at the top of the entanglement cavity spray fluid jets to the fiber web to entangle the fiber web; the entanglement cavity is in communication with a collection cover in the recycling unit, the collection cover is in turn in communication with a primary compression unit and a secondary compression unit, the primary compression unit and the secondary compression unit supply heat to a liquid carbon dioxide preheater; the secondary compression unit is in communication with the condensation liquefaction module; the condensation liquefaction module is in communication with the liquid carbon dioxide preheater; the liquid carbon dioxide preheater is in communication with the high-pressure fluid generation module; the high-pressure fluid generation module is in communication with a plurality of nozzles, in application, the fluid jets are gasified into low-pressure gaseous carbon dioxide in the entanglement cavity, the low-pressure gaseous carbon dioxide is then collected by the collection cover, and then compressed by the primary compression unit and the secondary compression unit to obtain high-pressure gaseous carbon dioxide, at the same time, the compression heat of the two units is supplied to the liquid carbon dioxide preheater; the high-pressure gaseous carbon dioxide is then condensed and liquefied in the condensation liquefaction module to obtain liquid carbon dioxide for storage; the liquid carbon dioxide is then preheated by the liquid carbon dioxide preheater, and then enters the high-pressure fluid generation module to become fluid carbon dioxide, which enters the nozzles as fluid jets to be sprayed, and the foregoing process is repeated until the non-woven fabric processing technology is completed, and the advantages of the present application further include:

[0034] Firstly, the present application not only uses non-aqueous medium fluid jets to replace water jets in the hydroentanglement process to achieve entanglement effect, but also recycles the carbon dioxide after the gasification of the fluid jets;

[0035] Secondly, the compression of gaseous carbon dioxide is divided into two times, which is easier to achieve than one-time compression under the condition of compressing the gas to the same pressure, and reduces the requirements for the compression equipment; and after the first compression, the temperature of the gaseous carbon dioxide approaches the ambient temperature, greatly reducing the temperature of the gaseous carbon dioxide entering the secondary compression, thereby significantly reducing the compression work and energy consumption during compression;

[0036] Thirdly, the heat generated by the primary compression unit and the secondary compression unit can be recycled; the heat is sent to the liquid carbon dioxide preheater for use, realizing the heat recycling function and reducing the energy consumption during heating;

[0037] Therefore, when the fiber web is entangled by using non-aqueous medium fluid, the energy consumption of fluid phase state treatment is low, and the heat recycling function is realized.

[0038] 2. In the energy coupling closed-loop recovery and pressurization system for carbon dioxide phase change fluid of the present invention, the condensation and liquefaction module includes a fine condenser and a liquid carbon dioxide storage tank. In application, the fine condenser condenses and liquefies gaseous carbon dioxide into completely homogeneous liquid carbon dioxide, ensuring stable storage of the liquid carbon dioxide in the storage tank. This prevents unstable mixing of liquid and gaseous carbon dioxide in the storage tank and allows the liquid carbon dioxide storage tank to supply completely liquid carbon dioxide to the liquid carbon dioxide preheater. Therefore, the liquid carbon dioxide storage effect in this invention is better.

[0039] 3. In the energy coupling closed-loop recovery and pressurization system for carbon dioxide phase change fluid of the present invention, the collection hood includes a high-pressure section, a mixing section, and a low-pressure section. The high-pressure section includes a high-pressure large end and a high-pressure small end with gradually decreasing diameters. The high-pressure small end is connected to one end of the mixing section, and the other end of the mixing section is connected to the low-pressure small end of the low-pressure section. The low-pressure small end is connected to the low-pressure large end, and the diameter of the low-pressure small end gradually increases from the low-pressure large end. The mixing section is connected to a suction pipe. In application, when the high-pressure fluid carbon dioxide flows sequentially through the high-pressure large end and the high-pressure small end, the diameter of the fluid carbon dioxide gradually decreases from the high-pressure large end to the high-pressure small end, thus accelerating the fluid carbon dioxide and forming a high-speed low-pressure jet. This jet is in the mixing section. The process involves internally drawing in gaseous carbon dioxide and exchanging momentum. As the mixed fluid passes through the low-pressure small end and the low-pressure large end, the flow velocity gradually decreases due to the increasing diameter of these ends. At this point, kinetic energy is converted into pressure energy, resulting in a fluid pressure greater than the pressure in the suction pipe. The fluid is then discharged through the low-pressure large end. During this process, the high-pressure carbon dioxide fluid pressurizes the drawn-in gaseous carbon dioxide, reducing the burden and energy consumption of subsequent primary and secondary compression units. Existing technologies, including passive collection methods such as cross-sectional contraction pipes, rely on the fluid's own pressure energy to generate suction force, further weakening the already low pressure of the gaseous carbon dioxide, and are therefore unsuitable for this invention. Consequently, this invention requires less compression work.

[0040] 4. In the energy coupling closed loop recycling pressurization system of the carbon dioxide phase change fluid, the high-pressure fluid generating module comprises a micro-channel heat exchanger, the micro-channel heat exchanger comprises a pressurizing unit, a plurality of high-pressure channels and low-pressure channels, adjacent high-pressure channels and low-pressure channels share a side wall, the side wall is made of a heat-conducting material, in application, the preheated liquid carbon dioxide flowing out of the liquid carbon dioxide preheater flows into the pressurizing unit through the low-pressure channels to be pressurized, and the high-pressure high-temperature fluid carbon dioxide after pressurization flows out through the high-pressure channels, in this process, the high-pressure high-temperature fluid carbon dioxide and the preheated liquid carbon dioxide exchange heat through the side wall, so that the temperature of the preheated liquid carbon dioxide can be increased, the heat burden of the subsequent pressurizing unit for heating the liquid carbon dioxide is reduced, and the energy consumption is also reduced. Therefore, the present application has a heat exchange function.

[0041] 5. In the energy coupling closed loop recycling pressurization system of the carbon dioxide phase change fluid, the liquid carbon dioxide preheater is a plate heat exchanger, the temperature at the outlet end of the plate heat exchanger is 25-31 DEG C, and the pressure is 1.8-2.2 MPa, the fine condenser adopts a variable frequency compression refrigeration system, in application, the liquid carbon dioxide is preheated through the plate heat exchanger, so that the temperature of the liquid carbon dioxide is 25-31 DEG C, so as to be close to the critical temperature, and the heat required for subsequent pressurization to the supercritical state (i.e. fluid state) can be greatly reduced; the fine condenser adopts a variable frequency compression refrigeration system, a low-temperature environment can be accurately controlled, and gaseous carbon dioxide is condensed in the low-temperature environment to form liquid carbon dioxide, so as to be stored in the liquid carbon dioxide storage tank. Therefore, the present application has good phase state control.

[0042] 6. In the energy coupling closed loop recycling pressurization system of the carbon dioxide phase change fluid, the system comprises an intelligent control system, the intelligent control system comprises sensors, an intelligent control unit and actuators installed at key nodes of the system, in application, the temperature, pressure and density of carbon dioxide at the key nodes of the system are monitored through the sensors, the monitoring data are transmitted to the intelligent control unit, then the intelligent control unit adjusts the parameters of the actuators, so that the carbon dioxide can be maintained in the expected phase state space, and the system can be stably and efficiently operated. Therefore, the present application has stable operation. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of the present application.

[0044] Figure 2 It is a flow chart of the present application.

[0045] Figure 3 It is a structural schematic diagram of heat transfer in the present application.

[0046] Figure 4 It is Figure 2Structure diagram of the collecting cover.

[0047] Figure 5 Structure diagram of Example 4.

[0048] Figure 6 Structure diagram of Example 5.

[0049] Figure 7 Structure diagram of Figure 2 Structure diagram of the entangling cavity.

[0050] Figure 8 State diagram of the fluid carbon dioxide in the application state.

[0051] In the figure: recovery unit 1, collecting cover 11, high-pressure section 111, mixing section 112, low-pressure section 113, suction pipeline 114, high-pressure large end 115, high-pressure small end 116, low-pressure small end 117, low-pressure large end 118, primary compression unit 12, secondary compression unit 13, liquid carbon dioxide preheater 2, high-pressure fluid generating module 3, micro-channel heat exchanger 31, low-pressure channel 311, high-pressure channel 312, side wall 313, pressurizing unit 32, entangling cavity 4, fiber web 41, nozzle 42, condensation liquefaction module 5, fine condenser 51, liquid carbon dioxide storage tank 52, sensor 6, intelligent control unit 61, actuator 62. DETAILED DESCRIPTION

[0052] The application is further described in detail in the following description and specific embodiments in conjunction with the accompanying drawings.

[0053] Please refer to Figure 1 — Figure 8 A carbon dioxide phase change fluid energy coupling closed loop recovery pressurization system, the system comprising an entangling cavity 4, a recovery unit 1, a condensation liquefaction module 5 and a high-pressure fluid generating module 3;

[0054] The middle part of the entangling cavity 4 is provided with a channel for the fiber web 41 to pass through, and the top part of the entangling cavity 4 is provided with a nozzle 42, which sprays fluid jets towards the direction of the fiber web 41, and the fluid jets entangle the fiber web 41;

[0055] The top part of the entangling cavity 4 is in communication with the input end of the collecting cover 11 in the recovery unit 1;

[0056] The output end of the collecting cover 11 is in communication with the input end of the primary compression unit 12, and the primary compression unit 12 supplies heat to the liquid carbon dioxide preheater 2;

[0057] The output end of the primary compression unit 12 is in communication with the input end of the secondary compression unit 13, and the secondary compression unit 13 supplies heat to the liquid carbon dioxide preheater 2;

[0058] An output end of the secondary compression unit 13 is in communication with an input end of the condensing liquefaction module 5;

[0059] An output end of the condensing liquefaction module 5 is in communication with an input end of the liquid carbon dioxide preheater 2;

[0060] An output end of the liquid carbon dioxide preheater 2 is in communication with an input end of the high-pressure fluid generation module 3;

[0061] An output end of the high-pressure fluid generation module 3 is in communication with input ends of the plurality of nozzles 42.

[0062] The condensing liquefaction module 5 comprises a fine condenser 51 and a liquid carbon dioxide storage tank 52, an input end of the fine condenser 51 is in communication with an output end of the secondary compression unit 13;

[0063] An output end of the fine condenser 51 is in communication with an input end of the liquid carbon dioxide storage tank 52;

[0064] An output end of the liquid carbon dioxide storage tank 52 is in communication with an input end of the liquid carbon dioxide preheater 2.

[0065] The collection cover 11 comprises a high-pressure section 111, a mixing section 112 and a low-pressure section 113;

[0066] The high-pressure section 111 comprises a high-pressure large end 115 and a high-pressure small end 116 which are in communication in sequence, a diameter of the high-pressure large end 115 to a diameter of the high-pressure small end 116 is gradually decreasing, one end of the high-pressure small end 116 is in communication with one end of the mixing section 112;

[0067] The other end of the mixing section 112 is in communication with one end of a low-pressure small end 117 in the low-pressure section 113, the other end of the low-pressure small end 117 is in communication with one end of a low-pressure large end 118, a diameter of the low-pressure small end 117 to a diameter of the low-pressure large end 118 is gradually increasing, the other end of the low-pressure large end 118 is in communication with an input end of the primary compression unit 12;

[0068] A middle part of the mixing section 112 is in vertical communication with one end of the suction duct 114, the other end of the suction duct 114 is in communication with a top part of the entangling cavity 4.

[0069] An entrainment ratio of the suction duct 114 to the high-pressure section 111 is three to one to ten to one.

[0070] The high-pressure section 111, the mixing section 112 and the low-pressure section 113 are made of stainless steel 316L material.

[0071] The high-pressure fluid generating module 3 comprises a micro-channel heat exchanger 31 and a pressurizing unit 32, the micro-channel heat exchanger 31 comprises a plurality of low-pressure channels 311 and a plurality of high-pressure channels 312, and adjacent high-pressure channels 312 and low-pressure channels 311 share a side wall 313, the side wall 313 is made of heat-conducting material;

[0072] The inlet end of the low-pressure channel 311 is communicated with the outlet end of the liquid carbon dioxide preheater 2, and the outlet end of the low-pressure channel 311 is communicated with the inlet end of the pressurizing unit 32; the outlet end of the pressurizing unit 32 is communicated with the inlet end of the high-pressure channel 312, and the outlet end of the high-pressure channel 312 is communicated with the input end of the plurality of nozzles 42.

[0073] The temperature in the high-pressure channel 312 is 35-60℃, and the temperature in the low-pressure channel 311 is 25-50℃.

[0074] The liquid carbon dioxide preheater 2 is a plate heat exchanger.

[0075] The temperature of the outlet end of the liquid carbon dioxide preheater 2 is 25-31℃.

[0076] The system comprises an intelligent control system, the intelligent control system comprises a sensor 6, an intelligent control unit 61 and an actuator 62, a plurality of the sensor 6 is respectively installed at the outlet end of the collecting cover 11, the outlet end of the primary compression unit 12, the outlet end of the secondary compression unit 13, the outlet end of the liquid carbon dioxide preheater 2, the outlet end of the high-pressure fluid generating module 3, the sensor 6 and the intelligent control unit 61 are signal connected, and the intelligent control unit 61 and the actuator 62 are signal connected.

[0077] The supplementary description of the application is as follows:

[0078] The phase state change of carbon dioxide in the application refers to that the phase state of carbon dioxide changes with temperature and pressure;

[0079] Liquid carbon dioxide: low-temperature and high-pressure state, suitable for storage and transportation;

[0080] Gaseous carbon dioxide: high-temperature and low-pressure state, i.e. the state of recovered gas;

[0081] Supercritical state: the temperature and pressure are higher than the critical point (the temperature is 31.1℃, and the pressure is 7.38MPa), carbon dioxide has the density similar to liquid and the diffusion similar to gas;

[0082] Solid carbon dioxide: low-temperature and low-pressure state, carbon dioxide exists in the form of dry ice;

[0083] Three-phase carbon dioxide: the temperature is-56.6℃, the pressure is 0.518MPa, and solid, liquid and gaseous carbon dioxide coexist.

[0084] Embodiment 1:

[0085] See Figure 1 — Figure 8 The energy coupling closed loop recovery pressurization system of carbon dioxide phase change fluid comprises a tangling cavity 4, a recovery unit 1, a condensation liquefaction module 5 and a high-pressure fluid generation module 3; a channel for the passage of a fiber web 41 is arranged in the middle of the tangling cavity 4, a nozzle 42 is arranged at the top of the tangling cavity 4, the nozzle 42 sprays fluid jets towards the direction of the fiber web 41, and the fluid jets tangle the fiber web 41; the top of the tangling cavity 4 is in communication with the input end of a collection cover 11 in the recovery unit 1; the output end of the collection cover 11 is in communication with the input end of a primary compression unit 12, the primary compression unit 12 supplies heat to a liquid carbon dioxide preheater 2; the output end of the primary compression unit 12 is in communication with the input end of a secondary compression unit 13, the secondary compression unit 13 supplies heat to the liquid carbon dioxide preheater 2; the output end of the secondary compression unit 13 is in communication with the input end of the condensation liquefaction module 5; the output end of the condensation liquefaction module 5 is in communication with the input end of the liquid carbon dioxide preheater 2; the output end of the liquid carbon dioxide preheater 2 is in communication with the input end of the high-pressure fluid generation module 3; and the output end of the high-pressure fluid generation module 3 is in communication with the input end of a plurality of nozzles 42.

[0086] In use, the fluid jet is first sprayed by the nozzle 42 towards the web 41, and then the web 41 is entangled by the fluid jet. After the entanglement by the fluid jet, the fluid jet is changed into gaseous carbon dioxide through a gasification process, and then the gaseous carbon dioxide is collected by the collection cover 11. Then, the gaseous carbon dioxide enters the primary compression unit 12 through a pipeline to be compressed for the first time. After the compression, the temperature of the gaseous carbon dioxide is adjusted to the ambient temperature. At this time, the compression heat of the first compression (the temperature of the heat medium is higher, about 80-100°C) is supplied to the liquid carbon dioxide preheater 2 through a pipeline. The gaseous carbon dioxide enters the secondary compression unit 13 through a pipeline to be compressed for the second time, so that the pressure of the gaseous carbon dioxide meets the requirements of the subsequent condensation process. At this time, the compression heat of the second compression is supplied to the liquid carbon dioxide preheater 2 through a pipeline (the temperature of the heat medium is lower, about 40-60°C). The compression is divided into two times, and the temperature of the gaseous carbon dioxide during the first compression is the ambient temperature, which can greatly reduce the compression work required by the secondary compression unit 13. The compression heat of the first compression and the compression heat of the second compression can reach 30-40% of the total energy consumption of the liquid carbon dioxide preheater 2, and the recovery efficiency reaches more than 80%. This breaks the mode that the compression heat is discarded as waste heat in the traditional system, forms an internal cycle of "compression-heat production-preheating-energy saving", and greatly reduces the external energy input. The gaseous carbon dioxide enters the condensation and liquefaction module 5 through a pipeline, and then the gaseous carbon dioxide is condensed and liquefied into liquid carbon dioxide, which is convenient for storage. The liquid carbon dioxide in the condensation and liquefaction module 5 first enters the liquid carbon dioxide preheater through a pipeline to be preheated until the temperature of the liquid carbon dioxide approaches the critical temperature (such as 28-31°C), which can greatly reduce the heat input required for subsequent pressurization to the supercritical state in the high-pressure fluid generation module 3, i.e. energy consumption. Then, the liquid carbon dioxide enters the high-pressure fluid generation module 3 through a pipeline to be pressurized until the liquid carbon dioxide becomes supercritical fluid carbon dioxide. The supercritical fluid carbon dioxide enters the nozzle 42 of the entanglement chamber 4 as a fluid jet, and the process is repeated until the non-woven fabric processing technology is completed.

[0087] Example 2:

[0088] The basic content is the same as that of Example 1, except that:

[0089] See Figure 1 — Figure 3The condensing and liquefying module 5 comprises a fine condenser 51 and a liquid carbon dioxide storage tank 52, the input end of the fine condenser 51 is communicated with the output end of the secondary compression unit 13; the output end of the fine condenser 51 is communicated with the input end of the liquid carbon dioxide storage tank 52; the output end of the liquid carbon dioxide storage tank 52 is communicated with the input end of the liquid carbon dioxide preheater 2. The fine condenser 51 adopts a variable frequency compression refrigeration system. Preferably, the pressure in the output end of the fine condenser 51 is 7.38 MPa, and the temperature is about 20℃. Preferably, the temperature in the liquid carbon dioxide storage tank 52 is about -20℃.

[0090] In application, the gaseous carbon dioxide is compressed in the secondary compression unit 13, not only the pressure is increased, but also the temperature is sharply increased (the temperature is 40-50℃, and the pressure is 7.5 MPa), at this time, the gaseous carbon dioxide is not liquid that can be directly stored; therefore, the high-temperature and high-pressure gaseous carbon dioxide firstly enters the fine condenser 51 along the pipeline, under the accurately controlled temperature and pressure parameters, the carbon dioxide is completely and uniformly liquefied, the process is as follows: firstly, the heat of the gaseous carbon dioxide is absorbed by the low-temperature environment of the variable frequency compression refrigeration system in the fine condenser 51, then the gaseous carbon dioxide is forcibly cooled and phase changes, and is completely and uniformly condensed into liquid carbon dioxide (the pressure is stable, about 7.38 MPa, and the temperature is higher than the freezing point, about 20℃); the liquid carbon dioxide enters the liquid carbon dioxide storage tank 52 along the pipeline, which can avoid the unstable situation of the mixture of gaseous carbon dioxide and liquid carbon dioxide in the liquid carbon dioxide storage tank 52, and can ensure that the liquid carbon dioxide storage tank 52 can provide stable liquid carbon dioxide for the liquid carbon dioxide preheater 2; at the same time, the refrigeration capacity of the variable frequency compression refrigeration system is dynamically adjusted according to the real-time feedback of the temperature sensor, which not only ensures the liquefaction effect, but also avoids the energy waste caused by overcooling.

[0091] Example 3:

[0092] The basic content is the same as that in example 1, and the difference is that:

[0093] Please refer to Figure 1 — Figure 4The collecting cover 11 comprises a high-pressure section 111, a mixing section 112 and a low-pressure section 113. The high-pressure section 111 comprises a high-pressure large end 115 and a high-pressure small end 116 which are communicated in sequence. The diameter of the high-pressure large end 115 gradually decreases to the diameter of the high-pressure small end 116. One end of the high-pressure small end 116 is communicated with one end of the mixing section 112. The other end of the mixing section 112 is communicated with one end of a low-pressure small end 117 in the low-pressure section 113. The other end of the low-pressure small end 117 is communicated with one end of a low-pressure large end 118. The diameter of the low-pressure small end 117 gradually increases to the diameter of the low-pressure large end 118. The other end of the low-pressure large end 118 is communicated with the input end of the primary compression unit 12. The middle part of the mixing section 112 is vertically communicated with one end of a suction duct 114. The other end of the suction duct 114 is communicated with the top of the entangling cavity 4. The suction ratio of the suction duct 114 to the high-pressure section 111 is 3:1 to 10:1. The materials of the high-pressure section 111, the mixing section 112 and the low-pressure section 113 are stainless steel 316L.

[0094] In application, the high-pressure fluid carbon dioxide firstly enters the high-pressure large end 115 and then flows into the high-pressure small end 116. Since the diameter of the high-pressure large end 115 gradually decreases to the diameter of the high-pressure small end 116, the high-pressure fluid carbon dioxide is accelerated to become a high-speed low-pressure fluid jet. Then the high-speed low-pressure fluid jet sucks the low-pressure gaseous carbon dioxide in the suction duct 114 in the mixing section 112 and exchanges momentum, and then obtains mixed gas. The mixed gas firstly enters the low-pressure small end 117 and then enters the low-pressure large end 118. Since the diameter of the low-pressure small end 117 gradually increases to the diameter of the low-pressure large end 118, the kinetic energy of the mixed gas is converted into pressure energy. At this time, the pressure of the mixed gas is greater than the pressure of the suction duct 114, so the mixed gas is discharged through the low-pressure section 113. In this process, the gaseous carbon dioxide is pressurized to reduce the energy consumption of the subsequent primary compression unit 12 and secondary compression unit 13. Since the sucked gaseous carbon dioxide may contain moisture, the materials of the high-pressure section 111, the mixing section 112 and the low-pressure section 113 are stainless steel 316L to prevent corrosion.

[0095] Example 4:

[0096] The basic content is the same as that in Example 1, except that:

[0097] Please refer to Figure 1 — Figure 5The high-pressure fluid generation module 3 includes a microchannel heat exchanger 31 and a pressurization unit 32. The microchannel heat exchanger 31 includes multiple low-pressure channels 311 and multiple high-pressure channels 312. Adjacent high-pressure channels 312 and low-pressure channels 311 share a sidewall 313, which is made of a thermally conductive material. The inlet end of the low-pressure channel 311 is connected to the outlet end of the liquid carbon dioxide preheater 2, and the outlet end of the low-pressure channel 311 is connected to the inlet end of the pressurization unit 32. The outlet end of the pressurization unit 32 is connected to the inlet end of the high-pressure channel 312, and the outlet end of the high-pressure channel 312 is connected to the input end of multiple nozzles 42. The temperature inside the high-pressure channel 312 is 35-60℃, and the temperature inside the low-pressure channel 311 is 25-50℃. Preferably, the high-pressure fluid generation module 3 is a high-pressure plunger pump, with the microchannel heat exchanger 31 integrated into the pump head. The pump head is made of stainless steel or nickel alloy and can withstand pressures up to 30 MPa. A pressure relief valve and leakage detection are added to prevent the microchannel heat exchanger 31 from rupturing. Preferably, the outlet pressure of the high-pressure channel 312 is 12-20 MPa, and the temperature is 32-40°C.

[0098] In application, the preheated liquid carbon dioxide flowing from the liquid carbon dioxide preheater 2 first flows into the low-pressure channel 311, and then flows into the pressurization unit 32 for pressurization. Due to the compression process, high-pressure and high-temperature fluid carbon dioxide is obtained, and then the high-pressure and high-temperature fluid carbon dioxide flows into the high-pressure channel 312. The high-temperature and high-pressure fluid carbon dioxide enters from one side of the microchannel heat exchanger 31 and is distributed into thousands of high-pressure channels 312, while the preheated liquid carbon dioxide enters from the other side of the microchannel heat exchanger 31 and is distributed into thousands of low-pressure channels 311. The two fluids flow counterclockwise in closely adjacent channels. During the process, since the sidewall between the adjacent high-pressure channel 312 and low-pressure channel 311 is made of thermally conductive material, the heat of the high-temperature and high-pressure fluid carbon dioxide is efficiently transferred to the preheated liquid carbon dioxide through the sidewall to heat the preheated liquid carbon dioxide, forming a counter-current heat exchange effect to reduce the heating energy consumption in the pressurization unit 32. That is, the temperature of the high-temperature and high-pressure fluid carbon dioxide is cooled from 60°C to 35°C, and the temperature of the preheated liquid carbon dioxide is heated from 25°C to 50°C. Finally, the cooled high-pressure fluid flows out from one end of the microchannel heat exchanger 31, and the preheated liquid carbon dioxide flows out from the other end of the microchannel heat exchanger 31.

[0099] Example 5:

[0100] The basic content is the same as in Example 1, except that:

[0101] Please see Figure 1 — Figure 6, the system comprises an intelligent control system, the intelligent control system comprises sensors 6, an intelligent control unit 61 and an actuator 62, a plurality of the sensors 6 are respectively installed at the outlet end of the collection cover 11, the outlet end of the primary compression unit 12, the outlet end of the secondary compression unit 13, the outlet end of the liquid carbon dioxide preheater 2 and the outlet end of the high-pressure fluid generating module 3, the sensors 6 are signal connected with the intelligent control unit 61, and the intelligent control unit 61 is signal connected with the actuator 62. Preferably, the sensors 6 comprise temperature sensors, pressure sensors and densitometers. Preferably, the sensors 6 are Coriolis mass flow meters, which simultaneously measure density, temperature and flow rate with an accuracy of ±0.1%.

[0102] In application, the phase state of carbon dioxide is extremely sensitive to temperature and pressure, in order to avoid energy loss and system instability, therefore, sensors 6 are arranged at key nodes of the system, such as the outlet end of the collection cover 11, the outlet end of the primary compression unit 12, the outlet end of the secondary compression unit 13, the outlet end of the liquid carbon dioxide preheater 2 and the outlet end of the high-pressure fluid generating module 3, to collect temperature, pressure and density data of the fluid carbon dioxide, the temperature and pressure determine the phase state of the fluid carbon dioxide, and the density is a key parameter directly reflecting the phase state of the fluid carbon dioxide; the data of the sensors 6 are transmitted to the intelligent control unit 61, and then the parameters of the actuator 62 are adjusted by the intelligent control unit 61, so that the carbon dioxide is maintained in the expected phase state space;

[0103] Phase diagram model: a pressure-temperature-density model of the fluid carbon dioxide is established by using a NIST REFPROP database or a Peng-Robinson equation, and the foregoing model is embedded in the intelligent control unit 61;

[0104] The foregoing model is built in the intelligent control unit 61, and the temperature, pressure and density data collected by the temperature sensors, the pressure sensors and the densitometers are taken as input parameters, so that the phase state of the fluid is calculated and predicted in real time;

[0105] The control strategy is realized through the following steps:

[0106] (1) Data fusion of multiple sensors 6: temperature, pressure and density data are collected in real time at key nodes of the system;

[0107] (2) Real-time diagnosis of the phase state: the collected data are compared with the built-in phase diagram model to determine the current phase state;

[0108] (3) Trend prediction: based on model predictive control (MPC) or fuzzy logic control, the phase state evolution in a future period of time is predicted;

[0109] (4) Feedforward control: when it is predicted that the system will deviate from the safe operation window, the actuator 62 (such as valves, heat exchangers and pumps of various devices) is adjusted in advance.

[0110] Specifically, the system defines the safe operating window of each process section, such as the temperature of 25-31℃ at the outlet end of the liquid carbon dioxide preheater 2, and the supercritical region of 32-40℃ and 12-20 MPa at the outlet end of the high-pressure fluid generation module 3; when the sensor 6 data indicates that the fluid has a tendency to enter the two-phase region (i.e. mixed with gaseous carbon dioxide and liquid carbon dioxide), the intelligent control unit 61 will adjust the heat medium flow (i.e. liquid carbon dioxide preheater 2) or the compressor (i.e. primary compression unit 12, secondary compression unit 13) speed in advance to ensure that the system always operates along the optimal phase path;

[0111] For example: the intelligent control unit 61 calculates the superheat or subcooling of the fluid carbon dioxide in real time according to the temperature and pressure at the outlet end of the high-pressure fluid generation module 3, and if it is judged that the fluid carbon dioxide has the risk of cavitation in the gas phase before the nozzle 42, the heat distribution of the liquid carbon dioxide preheater 2 will be adjusted immediately to accurately heat the fluid carbon dioxide, ensuring that it is delivered to the nozzle 42 in a stable subcritical or supercritical state fluid;

[0112] Intelligent phase state feedforward control principle: based on the physical properties of carbon dioxide, the control logic is upgraded from traditional "passive response" (such as adjusting after temperature overshoot) to "active prediction and intervention"; by comparing the phase diagram model in real time, the parameters are adjusted in advance to avoid the system running in a non-ideal phase state (such as two-phase flow), thereby ensuring the stability of the process, the recovery efficiency and protecting the equipment;

[0113] It also includes a fault-tolerant mechanism: such as switching to a temperature-pressure-based estimation model when some sensors 6 fail;

[0114] A human-machine interface can also be added for HMI for monitoring and parameter setting, realizing remote control;

[0115] Intelligent phase state control effectively avoids common faults such as "ice blockage" and "cavitation in the gas phase", improving the stability and life of the continuous operation of the system.

[0116] Example 6:

[0117] The basic content is the same as that of Example 5, except that:

[0118] Please refer to Figure 8 , which is the flow path and phase change of carbon dioxide in the system;

[0119] Starting point (supplying carbon dioxide): liquid carbon dioxide storage tank 52, the temperature inside is about -20℃, the pressure is about 2 MPa, and the carbon dioxide inside is in liquid state;

[0120] Preheating path: liquid carbon dioxide storage tank 52→ liquid carbon dioxide preheater 2, in which the carbon dioxide is preheated to near the critical temperature, for example, the temperature is 30℃, the pressure is 2 MPa, and the carbon dioxide is still ensured to be in liquid state;

[0121] Pressurization and phase change path: liquid carbon dioxide preheater 2→ high-pressure fluid generation module 3, in which the carbon dioxide is isothermally (approximately) or slightly heated to supercritical state, for example, the temperature is 35℃, the pressure is 15 MPa, at this time, the carbon dioxide is a supercritical fluid, and this path should quickly pass through the critical point to avoid dramatic fluctuations in parameters near the critical point;

[0122] Application and recovery: at the nozzle 42, the supercritical carbon dioxide fluid jet is gasified to become low-temperature and low-pressure gas-liquid two-phase or gaseous carbon dioxide;

[0123] Recovery and pressurization path: nozzle 42→ liquid carbon dioxide storage tank 52, the recovered gaseous carbon dioxide is compressed, cooled, and liquefied to return to the liquid carbon dioxide storage tank 52, completing the cycle;

[0124] Among them, the target area to be controlled is:

[0125] Strictly avoid the two-phase region: liquid carbon dioxide storage tank 52→ liquid carbon dioxide preheater 2→ high-pressure fluid generation module 3, which must absolutely avoid the two-phase region to prevent cavitation damage to the high-pressure fluid generation module 3 and cause flow fluctuations;

[0126] The area that needs to be optimized and controlled: inside the high-pressure fluid generation module 3, due to the dramatic change in physical properties, the intelligent control unit 61 needs to be precisely and stably controlled.

[0127] Example 7:

[0128] The basic content is the same as that of example 1, except that:

[0129] Please refer to Figure 7 , first, the raw fibers for making non-woven fabric are made into a web 41, and then the web 41 is conveyed through the entangling chamber 4, in the process of passing through the entangling chamber 4, the supercritical carbon dioxide fluid jet penetrates or enters the web 41 to entangle the raw fibers in the web 41, until the web 41 is conveyed out of the entangling chamber 4; after the process of the supercritical carbon dioxide fluid jet penetrating or entering the web 41 is completed, the fluid jet is gasified in the entangling chamber 4 to generate gaseous carbon dioxide;

[0130] When the supercritical carbon dioxide fluid jet penetrates or enters the fiber web 41, the fluid jet will provide a mechanical impact force to hit the raw fiber in the fiber web 41, so that the raw fiber is displaced, inserted, and entangled to generate a function similar to the existing water jet;

[0131] The fluid jet will be gasified in the entangling cavity 4 to generate gaseous carbon dioxide. On the basis of the mechanical impact force, the process can provide additional gasification explosion force or gasification expansion force to act on the fiber or the fiber joint. Not only the type of force is enriched, but also the object of the force is enriched. The entangling efficiency is much higher than that of the water jet relying on the mechanical impact force. The reinforcement effect is improved.

[0132] The carbon dioxide phase change fluid is composed of non-water carbon dioxide. Compared with the existing water jet process, a large amount of water resources can be saved, and water consumption is greatly reduced. At the same time, because the jet is not dependent on water, the high-energy water treatment device (such as filtration, softening, and purification equipment) can be saved in the overall equipment, thereby greatly reducing the energy consumption.

[0133] In the design, after the fluid jet penetrates or enters the fiber web 41, it will be gasified in the entangling cavity 4 to generate gaseous carbon dioxide. The reinforced fiber web 41 does not need to be dried, so the drying device with high energy consumption can be saved.

[0134] The carbon dioxide phase change fluid in the design is composed of carbon dioxide. It is not only free of impurities, but also can ensure the stability of the subsequent fluid jet to improve the entangling effect. In addition, the gasification after the jet generates gaseous carbon dioxide, which can ensure that all substances constituting the fluid jet are not left on the non-woven fabric.

[0135] The carbon dioxide phase change fluid is an excellent natural solvent, which has strong dissolving capacity for oil stains, grease, and some additives. Therefore, the impurities such as spinning oil (such as oil on chemical fibers) and wax (such as wax on natural cellulose fibers such as cotton fibers and hemp fibers) on the fiber can be dissolved and removed in situ during the entangling of the raw fiber, so as to obtain a cleaner fiber surface, thereby improving the friction coefficient and facilitating the raw fiber to produce closer entanglement under the action of mechanical impact force, gasification explosion force, or expansion force, further improving the reinforcement effect and improving the strength of the non-woven fabric.

[0136] Example 8:

[0137] The basic content is the same as that of example 1, except that:

[0138] Please refer to Figure 1 — Figure 2The liquid carbon dioxide preheater 2 is a plate heat exchanger. Preferably, the temperature of the outlet end of the liquid carbon dioxide preheater 2 is 25-31℃. The heat medium of the plate heat exchanger is preferably a glycol-water solution (concentration 40-60%) with a working temperature range of -20℃-120℃, which is suitable for the system.

[0139] In application, the preheating temperature of the liquid carbon dioxide needs to be accurately controlled to avoid premature vaporization, and a PID controller can be used to adjust the flow of the heat medium. The liquid carbon dioxide preheater 2 can be any high-efficiency heat exchanger, not limited to a jacketed or plate heat exchanger, but preferably a plate heat exchanger. The plate heat exchanger has the advantages of high preheating efficiency and compact structure.

[0140] The above description is only the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art according to the disclosed content of the present application shall be included in the protection scope of the claims.

Claims

1. An energy coupled closed loop recovery pressurization system for a phase change fluid of carbon dioxide, characterized by: The system comprises an entanglement chamber (4), a recovery unit (1), a condensation and liquefaction module (5) and a high-pressure fluid generation module (3); The middle part of the entanglement chamber (4) is provided with a channel for the fiber web (41) to pass through, and the top of the entanglement chamber (4) is provided with a nozzle (42) which sprays fluid jet towards the direction of the fiber web (41), and the fluid jet entangles the fiber web (41); The top of the entanglement chamber (4) is in communication with the input end of the collection cover (11) in the recovery unit (1); The output end of the collection cover (11) is in communication with the input end of the primary compression unit (12), and the primary compression unit (12) supplies heat to the liquid carbon dioxide preheater (2); The output end of the primary compression unit (12) is in communication with the input end of the secondary compression unit (13), and the secondary compression unit (13) supplies heat to the liquid carbon dioxide preheater (2); The output end of the secondary compression unit (13) is in communication with the input end of the condensation and liquefaction module (5); The output end of the condensation and liquefaction module (5) is in communication with the input end of the liquid carbon dioxide preheater (2); The output end of the liquid carbon dioxide preheater (2) is in communication with the input end of the high-pressure fluid generation module (3); The output end of the high-pressure fluid generation module (3) is in communication with the input end of a plurality of nozzles (42).

2. The energy coupling closed loop recovery pressurization system of phase change carbon dioxide fluid of claim 1, wherein: The condensation and liquefaction module (5) comprises a fine condenser (51) and a liquid carbon dioxide storage tank (52), and the input end of the fine condenser (51) is in communication with the output end of the secondary compression unit (13); The output end of the fine condenser (51) is in communication with the input end of the liquid carbon dioxide storage tank (52); The output end of the liquid carbon dioxide storage tank (52) is in communication with the input end of the liquid carbon dioxide preheater (2).

3. The energy coupling closed loop recovery pressure charging system of a carbon dioxide phase change fluid of claim 1 or 2, characterized in that: The collection cover (11) comprises a high-pressure section (111), a mixing section (112) and a low-pressure section (113); The high-pressure section (111) comprises a high-pressure large end (115) and a high-pressure small end (116) which are in communication in sequence, the diameter of the high-pressure large end (115) gradually decreases to the diameter of the high-pressure small end (116), and one end of the high-pressure small end (116) is in communication with one end of the mixing section (112); The other end of the mixing section (112) is in communication with one end of a low-pressure small end (117) in the low-pressure section (113), the other end of the low-pressure small end (117) is in communication with one end of a low-pressure large end (118), the diameter of the low-pressure small end (117) gradually increases to the diameter of the low-pressure large end (118), and the other end of the low-pressure large end (118) is in communication with the input end of the primary compression unit (12); The middle part of the mixing section (112) is in vertical communication with one end of a suction pipeline (114), and the other end of the suction pipeline (114) is in communication with the top of the entanglement chamber (4).

4. The energy coupling closed loop recovery pressure boosting system of claim 3, wherein: The entrainment ratio of the suction pipeline (114) to the high-pressure section (111) is three to one to ten to one.

5. A closed loop energy coupling system for recovering and pressurizing carbon dioxide phase change fluid according to claim 4, wherein: The materials of the high-pressure section (111), the mixing section (112) and the low-pressure section (113) are stainless steel 316L.

6. The energy coupling closed loop recovery pressure boosting system of carbon dioxide phase change fluid according to claim 1 or 2, characterized in that: The high-pressure fluid generating module (3) comprises a micro-channel heat exchanger (31) and a pressurizing unit (32), the micro-channel heat exchanger (31) comprises a plurality of low-pressure channels (311) and a plurality of high-pressure channels (312), adjacent high-pressure channels (312) and low-pressure channels (311) share a side wall (313), the side wall (313) is made of heat-conducting material; The inlet end of the low-pressure channel (311) is communicated with the outlet end of the liquid carbon dioxide preheater (2), the outlet end of the low-pressure channel (311) is communicated with the inlet end of the pressurizing unit (32); the outlet end of the pressurizing unit (32) is communicated with the inlet end of the high-pressure channel (312), and the outlet end of the high-pressure channel (312) is communicated with the input end of the plurality of nozzles (42).

7. A closed loop energy coupling system for recovering and pressurizing carbon dioxide phase change fluid according to claim 6, wherein: The temperature in the high-pressure channel (312) is 35-60℃, and the temperature in the low-pressure channel (311) is 25-50℃.

8. The energy coupling closed loop recovery pressure boosting system of carbon dioxide phase change fluid according to claim 1 or 2, characterized in that: The liquid carbon dioxide preheater (2) is a plate heat exchanger.

9. A closed loop energy coupling system for recovering and pressurizing carbon dioxide phase change fluid according to claim 8, wherein: The temperature of the outlet end of the liquid carbon dioxide preheater (2) is 25-31℃.

10. The energy coupling closed loop recovery pressure boosting system of a phase change carbon dioxide fluid according to claim 1, characterized by: The system comprises an intelligent control system, the intelligent control system comprises a sensor (6), an intelligent control unit (61) and an actuator (62), a plurality of the sensor (6) are respectively installed at the outlet end of the collecting cover (11), the outlet end of the first-stage compression unit (12), the outlet end of the second-stage compression unit (13), the outlet end of the liquid carbon dioxide preheater (2), the outlet end of the high-pressure fluid generating module (3), the sensor (6) and the intelligent control unit (61) are signal connected, and the intelligent control unit (61) and the actuator (62) are signal connected.

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